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How can I unwrap a string in Swift to fix error?
I am trying to make an app that the user selects an option from a tableview cell but I get the error:
Value of optional type 'String?' must be unwrapped to a value of type 'String'
I get the error on the 5th line and line 16, both about "unwrapping an optional type".
I've tried adding a ! and searching on the Internet, but I couldn't find any information that could help me fix the error.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as? DataTableViewCell
cell?.img.image = UIImage(named: arr[indexPath.row]["name"!])
cell?.lbl.text = arr[indexPath.row]["name"]
cell?.lbl2.text = arr[indexPath.row]["subject"]
cell?.lbl3.text = arr[indexPath.row]["grade"]
return cell!
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vc = storyboard?.instantiateViewController(withIdentifier: "DetailViewController") as? DetailViewController
vc?.str = arr[indexPath.row]["name"]
navigationController?.pushViewController(vc!, animated: true)
}
I expect the program to run without errors.
swift
edited Jan 2 at 3:44
rmaddy
244k27323384
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
add a comment |
I am trying to make an app that the user selects an option from a tableview cell but I get the error:
Value of optional type 'String?' must be unwrapped to a value of type 'String'
I get the error on the 5th line and line 16, both about "unwrapping an optional type".
I've tried adding a ! and searching on the Internet, but I couldn't find any information that could help me fix the error.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as? DataTableViewCell
cell?.img.image = UIImage(named: arr[indexPath.row]["name"!])
cell?.lbl.text = arr[indexPath.row]["name"]
cell?.lbl2.text = arr[indexPath.row]["subject"]
cell?.lbl3.text = arr[indexPath.row]["grade"]
return cell!
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vc = storyboard?.instantiateViewController(withIdentifier: "DetailViewController") as? DetailViewController
vc?.str = arr[indexPath.row]["name"]
navigationController?.pushViewController(vc!, animated: true)
}
I expect the program to run without errors.
swift
edited Jan 2 at 3:44
rmaddy
244k27323384
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
Please read Swift Language Guide, The Basics - Optionals
– vadian
Jan 1 at 12:37
let name = are[indexPath.row][name] ?? "Jon"
– Arjun Patel
Jan 2 at 5:30
add a comment |
I am trying to make an app that the user selects an option from a tableview cell but I get the error:
Value of optional type 'String?' must be unwrapped to a value of type 'String'
I get the error on the 5th line and line 16, both about "unwrapping an optional type".
I've tried adding a ! and searching on the Internet, but I couldn't find any information that could help me fix the error.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as? DataTableViewCell
cell?.img.image = UIImage(named: arr[indexPath.row]["name"!])
cell?.lbl.text = arr[indexPath.row]["name"]
cell?.lbl2.text = arr[indexPath.row]["subject"]
cell?.lbl3.text = arr[indexPath.row]["grade"]
return cell!
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vc = storyboard?.instantiateViewController(withIdentifier: "DetailViewController") as? DetailViewController
vc?.str = arr[indexPath.row]["name"]
navigationController?.pushViewController(vc!, animated: true)
}
I expect the program to run without errors.
swift
edited Jan 2 at 3:44
rmaddy
244k27323384
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
I am trying to make an app that the user selects an option from a tableview cell but I get the error:
Value of optional type 'String?' must be unwrapped to a value of type 'String'
I get the error on the 5th line and line 16, both about "unwrapping an optional type".
I've tried adding a ! and searching on the Internet, but I couldn't find any information that could help me fix the error.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as? DataTableViewCell
cell?.img.image = UIImage(named: arr[indexPath.row]["name"!])
cell?.lbl.text = arr[indexPath.row]["name"]
cell?.lbl2.text = arr[indexPath.row]["subject"]
cell?.lbl3.text = arr[indexPath.row]["grade"]
return cell!
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vc = storyboard?.instantiateViewController(withIdentifier: "DetailViewController") as? DetailViewController
vc?.str = arr[indexPath.row]["name"]
navigationController?.pushViewController(vc!, animated: true)
}
I expect the program to run without errors.
swift
swift
edited Jan 2 at 3:44
rmaddy
244k27323384
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
edited Jan 2 at 3:44
rmaddy
244k27323384
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
edited Jan 2 at 3:44
rmaddy
244k27323384
edited Jan 2 at 3:44
rmaddy
244k27323384
edited Jan 2 at 3:44
rmaddy
244k27323384
244k27323384
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
asked Jan 1 at 12:29
Min Wook Edward SongMin Wook Edward Song
1
1
Please read Swift Language Guide, The Basics - Optionals
– vadian
Jan 1 at 12:37
let name = are[indexPath.row][name] ?? "Jon"
– Arjun Patel
Jan 2 at 5:30
add a comment |
Please read Swift Language Guide, The Basics - Optionals
– vadian
Jan 1 at 12:37
let name = are[indexPath.row][name] ?? "Jon"
– Arjun Patel
Jan 2 at 5:30
Please read Swift Language Guide, The Basics - Optionals
– vadian
Jan 1 at 12:37
Please read Swift Language Guide, The Basics - Optionals
– vadian
Jan 1 at 12:37
let name = are[indexPath.row][name] ?? "Jon"
– Arjun Patel
Jan 2 at 5:30
let name = are[indexPath.row][name] ?? "Jon"
– Arjun Patel
Jan 2 at 5:30
add a comment |
1 Answer
1
active
oldest
votes
From Swift documentation
Swift also introduces optional types, which handle the absence of a value. Optionals say either “there is a value, and it equals x” or “there isn’t a value at all”.
How to fix, you have to learn Optional Chaining.
What you have done is called forced unwrapping.
I think you will get all of your answers here.
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
From Swift documentation
Swift also introduces optional types, which handle the absence of a value. Optionals say either “there is a value, and it equals x” or “there isn’t a value at all”.
How to fix, you have to learn Optional Chaining.
What you have done is called forced unwrapping.
I think you will get all of your answers here.
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
add a comment |
From Swift documentation
Swift also introduces optional types, which handle the absence of a value. Optionals say either “there is a value, and it equals x” or “there isn’t a value at all”.
How to fix, you have to learn Optional Chaining.
What you have done is called forced unwrapping.
I think you will get all of your answers here.
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
add a comment |
From Swift documentation
Swift also introduces optional types, which handle the absence of a value. Optionals say either “there is a value, and it equals x” or “there isn’t a value at all”.
How to fix, you have to learn Optional Chaining.
What you have done is called forced unwrapping.
I think you will get all of your answers here.
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
From Swift documentation
Swift also introduces optional types, which handle the absence of a value. Optionals say either “there is a value, and it equals x” or “there isn’t a value at all”.
How to fix, you have to learn Optional Chaining.
What you have done is called forced unwrapping.
I think you will get all of your answers here.
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
answered Jan 1 at 12:36
Ankur LahiryAnkur Lahiry
33239
33239
add a comment |
add a comment |
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Please read Swift Language Guide, The Basics - Optionals
– vadian
Jan 1 at 12:37
let name = are[indexPath.row][name] ?? "Jon"
– Arjun Patel
Jan 2 at 5:30