Mixing
No apparent reason for index out of bound in a list (C#)? [duplicate]
This question already has an answer here:
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
3 answers
I am new to C# and I have wrote a program that gives me index out of bound in specific program. Theoretically I see no reason why should i get this. The error is outputted in console but doesn't crash the program.
I have 3 classes Logic, Student and Main. When I try to to print out a list of all the students I get an error.
Student contains a Name, FN, and array of grades in form of double.
in Student.cs
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
public Student (string namee, int FNe, double gradese)
{
name = namee;
FN = FNe;
grades = gradese;
}
public void print()
{
Console.WriteLine(name);
Console.WriteLine(FN);
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
Console.WriteLine($"average: {z/j}" );
}
In "logic.cs"
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
List<Student> myList = new List<Student>();
public void print()
{
for (int i = 0; i < myList.Count ; i++)
{
myList[i].print();
}
}
The error i get is this but in the console:
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
at ConsoleApp6.Student.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class1.cs:line 73
at ConsoleApp6.Logic.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class2.cs:line 37
at ConsoleApp6.Program.Main(String args) in C:UserssashkSourceReposConsoleApp6ConsoleApp6Program.cs:line 22
Press any key to continue . . .
Line 73 and 37 are the loops (while and for) respectively in Student and Logic
c# list console-application
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
marked as duplicate by mjwills, Servy c#
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Nov 19 '18 at 23:00
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
|
show 8 more comments
This question already has an answer here:
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
3 answers
I am new to C# and I have wrote a program that gives me index out of bound in specific program. Theoretically I see no reason why should i get this. The error is outputted in console but doesn't crash the program.
I have 3 classes Logic, Student and Main. When I try to to print out a list of all the students I get an error.
Student contains a Name, FN, and array of grades in form of double.
in Student.cs
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
public Student (string namee, int FNe, double gradese)
{
name = namee;
FN = FNe;
grades = gradese;
}
public void print()
{
Console.WriteLine(name);
Console.WriteLine(FN);
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
Console.WriteLine($"average: {z/j}" );
}
In "logic.cs"
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
List<Student> myList = new List<Student>();
public void print()
{
for (int i = 0; i < myList.Count ; i++)
{
myList[i].print();
}
}
The error i get is this but in the console:
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
at ConsoleApp6.Student.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class1.cs:line 73
at ConsoleApp6.Logic.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class2.cs:line 37
at ConsoleApp6.Program.Main(String args) in C:UserssashkSourceReposConsoleApp6ConsoleApp6Program.cs:line 22
Press any key to continue . . .
Line 73 and 37 are the loops (while and for) respectively in Student and Logic
c# list console-application
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
marked as duplicate by mjwills, Servy c#
Users with the c# badge can single-handedly close c# questions as duplicates and reopen them as needed.
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Nov 19 '18 at 23:00
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
It seems you are running out of the array boundary of the arraygrades. Why don't you use afor-loop instead of awhile-loop there? Likefor (int i = 0; i < grades.Length; i++)
– Markus Safar
Nov 19 '18 at 22:38
In the second one, you're not adding anything to myList. You need to check that myList.Count is greater than zero and then you won't get the outside of bounds error. As myList has no values added, its trying to access -1 which doesn't exist.
– MiscellaneousUser
Nov 19 '18 at 22:38
1
The code shown tries to iterate an empty list. Why not simply use foreach instead?
– Filburt
Nov 19 '18 at 22:39
1
You also have a logic error in your logic.cs for loop. How many times do you think your loop will run if you only have one item inmyList? Hint: ifi == 0andmyList.Count == 1, what do you think will happen in the expressioni < myList.Count - 1?
– Chris
Nov 19 '18 at 22:43
1
@JatosDetking Please stop commenting and work on a Minimal, Complete, and Verifiable example that we can copy and paste and run on our end. The general problem here is simple - you are asking for an index that doesn't exist (see the duplicate link). If you want more specific advice then you need to show us code that compiles.
– mjwills
Nov 19 '18 at 22:53
|
show 8 more comments
This question already has an answer here:
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
3 answers
I am new to C# and I have wrote a program that gives me index out of bound in specific program. Theoretically I see no reason why should i get this. The error is outputted in console but doesn't crash the program.
I have 3 classes Logic, Student and Main. When I try to to print out a list of all the students I get an error.
Student contains a Name, FN, and array of grades in form of double.
in Student.cs
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
public Student (string namee, int FNe, double gradese)
{
name = namee;
FN = FNe;
grades = gradese;
}
public void print()
{
Console.WriteLine(name);
Console.WriteLine(FN);
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
Console.WriteLine($"average: {z/j}" );
}
In "logic.cs"
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
List<Student> myList = new List<Student>();
public void print()
{
for (int i = 0; i < myList.Count ; i++)
{
myList[i].print();
}
}
The error i get is this but in the console:
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
at ConsoleApp6.Student.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class1.cs:line 73
at ConsoleApp6.Logic.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class2.cs:line 37
at ConsoleApp6.Program.Main(String args) in C:UserssashkSourceReposConsoleApp6ConsoleApp6Program.cs:line 22
Press any key to continue . . .
Line 73 and 37 are the loops (while and for) respectively in Student and Logic
c# list console-application
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
This question already has an answer here:
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
3 answers
I am new to C# and I have wrote a program that gives me index out of bound in specific program. Theoretically I see no reason why should i get this. The error is outputted in console but doesn't crash the program.
I have 3 classes Logic, Student and Main. When I try to to print out a list of all the students I get an error.
Student contains a Name, FN, and array of grades in form of double.
in Student.cs
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
public Student (string namee, int FNe, double gradese)
{
name = namee;
FN = FNe;
grades = gradese;
}
public void print()
{
Console.WriteLine(name);
Console.WriteLine(FN);
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
Console.WriteLine($"average: {z/j}" );
}
In "logic.cs"
The students are added into a list(not shown here) also the grades are with capacity of 40 but student doesn't practically have 40 grades so the empty spaces are nulls->
List<Student> myList = new List<Student>();
public void print()
{
for (int i = 0; i < myList.Count ; i++)
{
myList[i].print();
}
}
The error i get is this but in the console:
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
at ConsoleApp6.Student.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class1.cs:line 73
at ConsoleApp6.Logic.print() in C:UserssashkSourceReposConsoleApp6ConsoleApp6Class2.cs:line 37
at ConsoleApp6.Program.Main(String args) in C:UserssashkSourceReposConsoleApp6ConsoleApp6Program.cs:line 22
Press any key to continue . . .
Line 73 and 37 are the loops (while and for) respectively in Student and Logic
This question already has an answer here:
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
3 answers
c# list console-application
c# list console-application
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
edited Nov 19 '18 at 23:01
Markus Safar
4,66641837
4,66641837
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
asked Nov 19 '18 at 22:34
Jatos DetkingJatos Detking
34
34
marked as duplicate by mjwills, Servy c#
Users with the c# badge can single-handedly close c# questions as duplicates and reopen them as needed.
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Nov 19 '18 at 23:00
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
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Nov 19 '18 at 23:00
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
It seems you are running out of the array boundary of the arraygrades. Why don't you use afor-loop instead of awhile-loop there? Likefor (int i = 0; i < grades.Length; i++)
– Markus Safar
Nov 19 '18 at 22:38
In the second one, you're not adding anything to myList. You need to check that myList.Count is greater than zero and then you won't get the outside of bounds error. As myList has no values added, its trying to access -1 which doesn't exist.
– MiscellaneousUser
Nov 19 '18 at 22:38
1
The code shown tries to iterate an empty list. Why not simply use foreach instead?
– Filburt
Nov 19 '18 at 22:39
1
You also have a logic error in your logic.cs for loop. How many times do you think your loop will run if you only have one item inmyList? Hint: ifi == 0andmyList.Count == 1, what do you think will happen in the expressioni < myList.Count - 1?
– Chris
Nov 19 '18 at 22:43
1
@JatosDetking Please stop commenting and work on a Minimal, Complete, and Verifiable example that we can copy and paste and run on our end. The general problem here is simple - you are asking for an index that doesn't exist (see the duplicate link). If you want more specific advice then you need to show us code that compiles.
– mjwills
Nov 19 '18 at 22:53
|
show 8 more comments
It seems you are running out of the array boundary of the arraygrades. Why don't you use afor-loop instead of awhile-loop there? Likefor (int i = 0; i < grades.Length; i++)
– Markus Safar
Nov 19 '18 at 22:38
In the second one, you're not adding anything to myList. You need to check that myList.Count is greater than zero and then you won't get the outside of bounds error. As myList has no values added, its trying to access -1 which doesn't exist.
– MiscellaneousUser
Nov 19 '18 at 22:38
1
The code shown tries to iterate an empty list. Why not simply use foreach instead?
– Filburt
Nov 19 '18 at 22:39
1
You also have a logic error in your logic.cs for loop. How many times do you think your loop will run if you only have one item inmyList? Hint: ifi == 0andmyList.Count == 1, what do you think will happen in the expressioni < myList.Count - 1?
– Chris
Nov 19 '18 at 22:43
1
@JatosDetking Please stop commenting and work on a Minimal, Complete, and Verifiable example that we can copy and paste and run on our end. The general problem here is simple - you are asking for an index that doesn't exist (see the duplicate link). If you want more specific advice then you need to show us code that compiles.
– mjwills
Nov 19 '18 at 22:53
It seems you are running out of the array boundary of the array
grades. Why don't you use a for-loop instead of a while-loop there? Like for (int i = 0; i < grades.Length; i++)– Markus Safar
Nov 19 '18 at 22:38
It seems you are running out of the array boundary of the array
grades. Why don't you use a for-loop instead of a while-loop there? Like for (int i = 0; i < grades.Length; i++)– Markus Safar
Nov 19 '18 at 22:38
In the second one, you're not adding anything to myList. You need to check that myList.Count is greater than zero and then you won't get the outside of bounds error. As myList has no values added, its trying to access -1 which doesn't exist.
– MiscellaneousUser
Nov 19 '18 at 22:38
In the second one, you're not adding anything to myList. You need to check that myList.Count is greater than zero and then you won't get the outside of bounds error. As myList has no values added, its trying to access -1 which doesn't exist.
– MiscellaneousUser
Nov 19 '18 at 22:38
1
1
The code shown tries to iterate an empty list. Why not simply use foreach instead?
– Filburt
Nov 19 '18 at 22:39
The code shown tries to iterate an empty list. Why not simply use foreach instead?
– Filburt
Nov 19 '18 at 22:39
1
1
You also have a logic error in your logic.cs for loop. How many times do you think your loop will run if you only have one item in
myList? Hint: if i == 0 and myList.Count == 1, what do you think will happen in the expression i < myList.Count - 1?– Chris
Nov 19 '18 at 22:43
You also have a logic error in your logic.cs for loop. How many times do you think your loop will run if you only have one item in
myList? Hint: if i == 0 and myList.Count == 1, what do you think will happen in the expression i < myList.Count - 1?– Chris
Nov 19 '18 at 22:43
1
1
@JatosDetking Please stop commenting and work on a Minimal, Complete, and Verifiable example that we can copy and paste and run on our end. The general problem here is simple - you are asking for an index that doesn't exist (see the duplicate link). If you want more specific advice then you need to show us code that compiles.
– mjwills
Nov 19 '18 at 22:53
@JatosDetking Please stop commenting and work on a Minimal, Complete, and Verifiable example that we can copy and paste and run on our end. The general problem here is simple - you are asking for an index that doesn't exist (see the duplicate link). If you want more specific advice then you need to show us code that compiles.
– mjwills
Nov 19 '18 at 22:53
|
show 8 more comments
2 Answers
2
active
oldest
votes
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
indicates that you are running out of the array boundary of the array grades.
while(grades[j] != 0)
{
...
j++;
}
...is not the correct way, you need to check for the array boundary.
And you could combine this with a for loop like this:
for (int i = 0; i < grades.Length; i++)
{
...
}
And instead of this
...
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
...
you probably want something like this
...
double average = CalculateAverage(grades);
...
private double CalculateAverage(double grades)
{
double sum = 0;
int numberOfGrades = 0;
for (int i = 0; i < grades.Length; i++)
{
if (grades[i] == 0)
continue;
sum += grades[i];
numberOfGrades++;
}
return sum / numberOfGrades;
}
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
add a comment |
Change your for loop to use a foreach loop
Change this:
for (int i = 0; i < myList.Count - 1; i++)
{
myList[i].print();
}
To this:
foreach(var student in myList) {
student.print();
}
A for-each loop will iterate over every element. You do not increment i in this case anywhere else in your code, so using a for-each is recommended.
answered Nov 19 '18 at 22:40
DomDom
111214
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
indicates that you are running out of the array boundary of the array grades.
while(grades[j] != 0)
{
...
j++;
}
...is not the correct way, you need to check for the array boundary.
And you could combine this with a for loop like this:
for (int i = 0; i < grades.Length; i++)
{
...
}
And instead of this
...
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
...
you probably want something like this
...
double average = CalculateAverage(grades);
...
private double CalculateAverage(double grades)
{
double sum = 0;
int numberOfGrades = 0;
for (int i = 0; i < grades.Length; i++)
{
if (grades[i] == 0)
continue;
sum += grades[i];
numberOfGrades++;
}
return sum / numberOfGrades;
}
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
add a comment |
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
indicates that you are running out of the array boundary of the array grades.
while(grades[j] != 0)
{
...
j++;
}
...is not the correct way, you need to check for the array boundary.
And you could combine this with a for loop like this:
for (int i = 0; i < grades.Length; i++)
{
...
}
And instead of this
...
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
...
you probably want something like this
...
double average = CalculateAverage(grades);
...
private double CalculateAverage(double grades)
{
double sum = 0;
int numberOfGrades = 0;
for (int i = 0; i < grades.Length; i++)
{
if (grades[i] == 0)
continue;
sum += grades[i];
numberOfGrades++;
}
return sum / numberOfGrades;
}
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
add a comment |
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
indicates that you are running out of the array boundary of the array grades.
while(grades[j] != 0)
{
...
j++;
}
...is not the correct way, you need to check for the array boundary.
And you could combine this with a for loop like this:
for (int i = 0; i < grades.Length; i++)
{
...
}
And instead of this
...
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
...
you probably want something like this
...
double average = CalculateAverage(grades);
...
private double CalculateAverage(double grades)
{
double sum = 0;
int numberOfGrades = 0;
for (int i = 0; i < grades.Length; i++)
{
if (grades[i] == 0)
continue;
sum += grades[i];
numberOfGrades++;
}
return sum / numberOfGrades;
}
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
indicates that you are running out of the array boundary of the array grades.
while(grades[j] != 0)
{
...
j++;
}
...is not the correct way, you need to check for the array boundary.
And you could combine this with a for loop like this:
for (int i = 0; i < grades.Length; i++)
{
...
}
And instead of this
...
double z = 0;
int j = 0;
while(grades[j] != 0)
{
Console.Write(grades[j]);
z += grades[j];
j++;
}
...
you probably want something like this
...
double average = CalculateAverage(grades);
...
private double CalculateAverage(double grades)
{
double sum = 0;
int numberOfGrades = 0;
for (int i = 0; i < grades.Length; i++)
{
if (grades[i] == 0)
continue;
sum += grades[i];
numberOfGrades++;
}
return sum / numberOfGrades;
}
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
edited Nov 19 '18 at 23:00
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
answered Nov 19 '18 at 22:45
Markus SafarMarkus Safar
4,66641837
4,66641837
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
add a comment |
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
But what if the grades are like array is 40 elements long but i fill only 20 for example? i want the average only of these 20 , the others will be nulls? Like I make array of X elements but I fill only Y elements, does it .AverageWork with Doubles
– Jatos Detking
Nov 19 '18 at 22:48
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking, Then you either have to remember the number of values in the array somewhere - like as integer value in an integer variable or you can use another data structure that is able to grow and shrink dynamically, like a generic list. Another way is to exclude the value "0" as it most likely is not a valid grade.
– Markus Safar
Nov 19 '18 at 22:50
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
@JatosDetking: You can also make the condition be an AND condition: (grades[j] != 0 && j < grades.Length), assuming all zeros are at the tail end of the array.
– Filip Milovanović
Nov 19 '18 at 23:04
add a comment |
Change your for loop to use a foreach loop
Change this:
for (int i = 0; i < myList.Count - 1; i++)
{
myList[i].print();
}
To this:
foreach(var student in myList) {
student.print();
}
A for-each loop will iterate over every element. You do not increment i in this case anywhere else in your code, so using a for-each is recommended.
answered Nov 19 '18 at 22:40
DomDom
111214
add a comment |
Change your for loop to use a foreach loop
Change this:
for (int i = 0; i < myList.Count - 1; i++)
{
myList[i].print();
}
To this:
foreach(var student in myList) {
student.print();
}
A for-each loop will iterate over every element. You do not increment i in this case anywhere else in your code, so using a for-each is recommended.
answered Nov 19 '18 at 22:40
DomDom
111214
add a comment |
Change your for loop to use a foreach loop
Change this:
for (int i = 0; i < myList.Count - 1; i++)
{
myList[i].print();
}
To this:
foreach(var student in myList) {
student.print();
}
A for-each loop will iterate over every element. You do not increment i in this case anywhere else in your code, so using a for-each is recommended.
answered Nov 19 '18 at 22:40
DomDom
111214
Change your for loop to use a foreach loop
Change this:
for (int i = 0; i < myList.Count - 1; i++)
{
myList[i].print();
}
To this:
foreach(var student in myList) {
student.print();
}
A for-each loop will iterate over every element. You do not increment i in this case anywhere else in your code, so using a for-each is recommended.
answered Nov 19 '18 at 22:40
DomDom
111214
answered Nov 19 '18 at 22:40
DomDom
111214
answered Nov 19 '18 at 22:40
DomDom
111214
answered Nov 19 '18 at 22:40
DomDom
111214
111214
add a comment |
add a comment |
It seems you are running out of the array boundary of the array
grades. Why don't you use afor-loop instead of awhile-loop there? Likefor (int i = 0; i < grades.Length; i++)– Markus Safar
Nov 19 '18 at 22:38
In the second one, you're not adding anything to myList. You need to check that myList.Count is greater than zero and then you won't get the outside of bounds error. As myList has no values added, its trying to access -1 which doesn't exist.
– MiscellaneousUser
Nov 19 '18 at 22:38
1
The code shown tries to iterate an empty list. Why not simply use foreach instead?
– Filburt
Nov 19 '18 at 22:39
1
You also have a logic error in your logic.cs for loop. How many times do you think your loop will run if you only have one item in
myList? Hint: ifi == 0andmyList.Count == 1, what do you think will happen in the expressioni < myList.Count - 1?– Chris
Nov 19 '18 at 22:43
1
@JatosDetking Please stop commenting and work on a Minimal, Complete, and Verifiable example that we can copy and paste and run on our end. The general problem here is simple - you are asking for an index that doesn't exist (see the duplicate link). If you want more specific advice then you need to show us code that compiles.
– mjwills
Nov 19 '18 at 22:53