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How to get value from matching key from keyvalue pair list in vb.net using linq?
I want to have the value from keyvalue pair list which key matches the given data.
I have data in list as follows
LeftExistingLayerName
(0)=>{[data1, 0.04#0]}
(1)=>{[data2, 0.04#0]}
(2)=>{[data3, 0.04#0]}
I have used following code to get the single value e.g matching data1
Dim LeftExistingLayerName As List(Of KeyValuePair(Of String, String)) = New List(Of KeyValuePair(Of String, String))
Dim result As String()
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
Dim result1 = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.ToString()
result = result1.Split(New String() {"#"}, StringSplitOptions.None)
End If
I want to have the value in the string reslut1 and split "#" and take out the values 0.04 in result(0) and 0 in result1
I am getting this error
Conversion from string "System.Linq.Enumerable+WhereSele" to type 'Double' is not valid
vb.net linq
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
add a comment |
I want to have the value from keyvalue pair list which key matches the given data.
I have data in list as follows
LeftExistingLayerName
(0)=>{[data1, 0.04#0]}
(1)=>{[data2, 0.04#0]}
(2)=>{[data3, 0.04#0]}
I have used following code to get the single value e.g matching data1
Dim LeftExistingLayerName As List(Of KeyValuePair(Of String, String)) = New List(Of KeyValuePair(Of String, String))
Dim result As String()
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
Dim result1 = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.ToString()
result = result1.Split(New String() {"#"}, StringSplitOptions.None)
End If
I want to have the value in the string reslut1 and split "#" and take out the values 0.04 in result(0) and 0 in result1
I am getting this error
Conversion from string "System.Linq.Enumerable+WhereSele" to type 'Double' is not valid
vb.net linq
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
2
The result of a LINQ query is an enumerable list. If you want one item from that list then useFirst,FirstOrDefault,SingleorSingleOrDefault. Note that there is never a case where more than one of those methods is appropriate. They are for lists containing one or more items, zero or one or more items, one item and zero or one item respectively.
– jmcilhinney
Nov 22 '18 at 11:19
add a comment |
I want to have the value from keyvalue pair list which key matches the given data.
I have data in list as follows
LeftExistingLayerName
(0)=>{[data1, 0.04#0]}
(1)=>{[data2, 0.04#0]}
(2)=>{[data3, 0.04#0]}
I have used following code to get the single value e.g matching data1
Dim LeftExistingLayerName As List(Of KeyValuePair(Of String, String)) = New List(Of KeyValuePair(Of String, String))
Dim result As String()
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
Dim result1 = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.ToString()
result = result1.Split(New String() {"#"}, StringSplitOptions.None)
End If
I want to have the value in the string reslut1 and split "#" and take out the values 0.04 in result(0) and 0 in result1
I am getting this error
Conversion from string "System.Linq.Enumerable+WhereSele" to type 'Double' is not valid
vb.net linq
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
I want to have the value from keyvalue pair list which key matches the given data.
I have data in list as follows
LeftExistingLayerName
(0)=>{[data1, 0.04#0]}
(1)=>{[data2, 0.04#0]}
(2)=>{[data3, 0.04#0]}
I have used following code to get the single value e.g matching data1
Dim LeftExistingLayerName As List(Of KeyValuePair(Of String, String)) = New List(Of KeyValuePair(Of String, String))
Dim result As String()
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
Dim result1 = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.ToString()
result = result1.Split(New String() {"#"}, StringSplitOptions.None)
End If
I want to have the value in the string reslut1 and split "#" and take out the values 0.04 in result(0) and 0 in result1
I am getting this error
Conversion from string "System.Linq.Enumerable+WhereSele" to type 'Double' is not valid
vb.net linq
vb.net linq
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
asked Nov 22 '18 at 9:56
ritesh khadkaritesh khadka
829
829
2
The result of a LINQ query is an enumerable list. If you want one item from that list then useFirst,FirstOrDefault,SingleorSingleOrDefault. Note that there is never a case where more than one of those methods is appropriate. They are for lists containing one or more items, zero or one or more items, one item and zero or one item respectively.
– jmcilhinney
Nov 22 '18 at 11:19
add a comment |
2
The result of a LINQ query is an enumerable list. If you want one item from that list then useFirst,FirstOrDefault,SingleorSingleOrDefault. Note that there is never a case where more than one of those methods is appropriate. They are for lists containing one or more items, zero or one or more items, one item and zero or one item respectively.
– jmcilhinney
Nov 22 '18 at 11:19
2
2
The result of a LINQ query is an enumerable list. If you want one item from that list then use
First, FirstOrDefault, Single or SingleOrDefault. Note that there is never a case where more than one of those methods is appropriate. They are for lists containing one or more items, zero or one or more items, one item and zero or one item respectively.– jmcilhinney
Nov 22 '18 at 11:19
The result of a LINQ query is an enumerable list. If you want one item from that list then use
First, FirstOrDefault, Single or SingleOrDefault. Note that there is never a case where more than one of those methods is appropriate. They are for lists containing one or more items, zero or one or more items, one item and zero or one item respectively.– jmcilhinney
Nov 22 '18 at 11:19
add a comment |
1 Answer
1
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oldest
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You're not showing the code that is causing the problem as the error states there was an issue when "attempting to convert a string to a double". Nothing in your code illustrates this.
Anyhow, to the point...
The string "System.Linq.Enumerable+WhereSele" is clearly not what you want to convert to a double value. The string representation comes from the fact that you're invoking ToString() on an Enumerable returned from the Select clause then trying to convert that to a double.
Given you've said that:
I have used following code to get the single value e.g matching data1
We can agree that you're expecting a single value back from the Enumerable query, As @jmcilhinney has suggested in the comments there are various methods that do this for you each of which are made for a specific scenario.
i.e.
- First
- FirstOrDefault
- Single
- SingleOrDefault
I'll let you investigate the little details that differentiate them, but for now and for example purposes you can use FirstOrDefault.
So, your code becomes:
Dim result As String = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault()
reads as "return the first value of the KeyValuePair where the KeyValuePair's key contains g.LayerName otherwise the default value of a reference type"
So, at this point, we can then split the string by the delimiter "#" and covert the first, second items of the array to a double or any other type.
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
.Split(New String() {"#"}, StringSplitOptions.None)
' array(0) gets the 0.04 part of your example
' array(1) gets the 0 part of your example
This should suffice as long as the predicate Function(x) x.Key.Contains(s) is always guaranteed to be met. Otherwise, you'll get a NullReferenceException upon invoking .Split on a null reference returned by FirstOrDefault.
If you want to handle that scenario then you can use the null propagation operator (?).
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
?.Split(New String() {"#"}, StringSplitOptions.None)
Btw, you can simplify:
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
to:
If LeftExistingLayerName.Any(Function(x) x.Key.Contains(g.LayerName)) Then
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
1
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
add a comment |
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1 Answer
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active
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1 Answer
1
active
oldest
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active
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You're not showing the code that is causing the problem as the error states there was an issue when "attempting to convert a string to a double". Nothing in your code illustrates this.
Anyhow, to the point...
The string "System.Linq.Enumerable+WhereSele" is clearly not what you want to convert to a double value. The string representation comes from the fact that you're invoking ToString() on an Enumerable returned from the Select clause then trying to convert that to a double.
Given you've said that:
I have used following code to get the single value e.g matching data1
We can agree that you're expecting a single value back from the Enumerable query, As @jmcilhinney has suggested in the comments there are various methods that do this for you each of which are made for a specific scenario.
i.e.
- First
- FirstOrDefault
- Single
- SingleOrDefault
I'll let you investigate the little details that differentiate them, but for now and for example purposes you can use FirstOrDefault.
So, your code becomes:
Dim result As String = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault()
reads as "return the first value of the KeyValuePair where the KeyValuePair's key contains g.LayerName otherwise the default value of a reference type"
So, at this point, we can then split the string by the delimiter "#" and covert the first, second items of the array to a double or any other type.
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
.Split(New String() {"#"}, StringSplitOptions.None)
' array(0) gets the 0.04 part of your example
' array(1) gets the 0 part of your example
This should suffice as long as the predicate Function(x) x.Key.Contains(s) is always guaranteed to be met. Otherwise, you'll get a NullReferenceException upon invoking .Split on a null reference returned by FirstOrDefault.
If you want to handle that scenario then you can use the null propagation operator (?).
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
?.Split(New String() {"#"}, StringSplitOptions.None)
Btw, you can simplify:
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
to:
If LeftExistingLayerName.Any(Function(x) x.Key.Contains(g.LayerName)) Then
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
1
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
add a comment |
You're not showing the code that is causing the problem as the error states there was an issue when "attempting to convert a string to a double". Nothing in your code illustrates this.
Anyhow, to the point...
The string "System.Linq.Enumerable+WhereSele" is clearly not what you want to convert to a double value. The string representation comes from the fact that you're invoking ToString() on an Enumerable returned from the Select clause then trying to convert that to a double.
Given you've said that:
I have used following code to get the single value e.g matching data1
We can agree that you're expecting a single value back from the Enumerable query, As @jmcilhinney has suggested in the comments there are various methods that do this for you each of which are made for a specific scenario.
i.e.
- First
- FirstOrDefault
- Single
- SingleOrDefault
I'll let you investigate the little details that differentiate them, but for now and for example purposes you can use FirstOrDefault.
So, your code becomes:
Dim result As String = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault()
reads as "return the first value of the KeyValuePair where the KeyValuePair's key contains g.LayerName otherwise the default value of a reference type"
So, at this point, we can then split the string by the delimiter "#" and covert the first, second items of the array to a double or any other type.
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
.Split(New String() {"#"}, StringSplitOptions.None)
' array(0) gets the 0.04 part of your example
' array(1) gets the 0 part of your example
This should suffice as long as the predicate Function(x) x.Key.Contains(s) is always guaranteed to be met. Otherwise, you'll get a NullReferenceException upon invoking .Split on a null reference returned by FirstOrDefault.
If you want to handle that scenario then you can use the null propagation operator (?).
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
?.Split(New String() {"#"}, StringSplitOptions.None)
Btw, you can simplify:
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
to:
If LeftExistingLayerName.Any(Function(x) x.Key.Contains(g.LayerName)) Then
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
1
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
add a comment |
You're not showing the code that is causing the problem as the error states there was an issue when "attempting to convert a string to a double". Nothing in your code illustrates this.
Anyhow, to the point...
The string "System.Linq.Enumerable+WhereSele" is clearly not what you want to convert to a double value. The string representation comes from the fact that you're invoking ToString() on an Enumerable returned from the Select clause then trying to convert that to a double.
Given you've said that:
I have used following code to get the single value e.g matching data1
We can agree that you're expecting a single value back from the Enumerable query, As @jmcilhinney has suggested in the comments there are various methods that do this for you each of which are made for a specific scenario.
i.e.
- First
- FirstOrDefault
- Single
- SingleOrDefault
I'll let you investigate the little details that differentiate them, but for now and for example purposes you can use FirstOrDefault.
So, your code becomes:
Dim result As String = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault()
reads as "return the first value of the KeyValuePair where the KeyValuePair's key contains g.LayerName otherwise the default value of a reference type"
So, at this point, we can then split the string by the delimiter "#" and covert the first, second items of the array to a double or any other type.
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
.Split(New String() {"#"}, StringSplitOptions.None)
' array(0) gets the 0.04 part of your example
' array(1) gets the 0 part of your example
This should suffice as long as the predicate Function(x) x.Key.Contains(s) is always guaranteed to be met. Otherwise, you'll get a NullReferenceException upon invoking .Split on a null reference returned by FirstOrDefault.
If you want to handle that scenario then you can use the null propagation operator (?).
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
?.Split(New String() {"#"}, StringSplitOptions.None)
Btw, you can simplify:
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
to:
If LeftExistingLayerName.Any(Function(x) x.Key.Contains(g.LayerName)) Then
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
You're not showing the code that is causing the problem as the error states there was an issue when "attempting to convert a string to a double". Nothing in your code illustrates this.
Anyhow, to the point...
The string "System.Linq.Enumerable+WhereSele" is clearly not what you want to convert to a double value. The string representation comes from the fact that you're invoking ToString() on an Enumerable returned from the Select clause then trying to convert that to a double.
Given you've said that:
I have used following code to get the single value e.g matching data1
We can agree that you're expecting a single value back from the Enumerable query, As @jmcilhinney has suggested in the comments there are various methods that do this for you each of which are made for a specific scenario.
i.e.
- First
- FirstOrDefault
- Single
- SingleOrDefault
I'll let you investigate the little details that differentiate them, but for now and for example purposes you can use FirstOrDefault.
So, your code becomes:
Dim result As String = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault()
reads as "return the first value of the KeyValuePair where the KeyValuePair's key contains g.LayerName otherwise the default value of a reference type"
So, at this point, we can then split the string by the delimiter "#" and covert the first, second items of the array to a double or any other type.
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
.Split(New String() {"#"}, StringSplitOptions.None)
' array(0) gets the 0.04 part of your example
' array(1) gets the 0 part of your example
This should suffice as long as the predicate Function(x) x.Key.Contains(s) is always guaranteed to be met. Otherwise, you'll get a NullReferenceException upon invoking .Split on a null reference returned by FirstOrDefault.
If you want to handle that scenario then you can use the null propagation operator (?).
Dim array As String() = LeftExistingLayerName _
.Where(Function(x) x.Key.Contains(g.LayerName)) _
.Select(Function(x) x.Value) _
.FirstOrDefault() _
?.Split(New String() {"#"}, StringSplitOptions.None)
Btw, you can simplify:
If LeftExistingLayerName.Where(Function(x) x.Key.Contains(g.LayerName)).Any() Then
to:
If LeftExistingLayerName.Any(Function(x) x.Key.Contains(g.LayerName)) Then
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
edited Nov 22 '18 at 19:32
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
answered Nov 22 '18 at 19:17
AomineAomine
42.3k74473
42.3k74473
1
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
add a comment |
1
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
1
1
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
Thank you. That worked like a charm. Learned a lot from your answer
– ritesh khadka
Nov 23 '18 at 7:16
add a comment |
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2
The result of a LINQ query is an enumerable list. If you want one item from that list then use
First,FirstOrDefault,SingleorSingleOrDefault. Note that there is never a case where more than one of those methods is appropriate. They are for lists containing one or more items, zero or one or more items, one item and zero or one item respectively.– jmcilhinney
Nov 22 '18 at 11:19