Swift Array Index Out of Range and Nil Values
I have a JSON get request where I retrieve information about four users and then load four views with their pictures, names, etc.
I also have a function where the user can tap on those views and view more information about them.
However, I need to make sure that the array (randomFour) containing the four users contains actual information for the view they are selecting and is not nil.
I attempted to do this by counting the indexes of the array, but for some reason it isn't preventing it from going through and then crashes because the values are nil.
@objc func loadWriteView(sender: UITapGestureRecognizer) {
if sender.view == a_view || sender.view == a_pic && randomFour.count >= 1 {
setupCardWrite(user: randomFour[0])
} else if sender.view == b_view || sender.view == b_pic && randomFour.count >= 2 {
setupCardWrite(user: randomFour[1])
} else if sender.view == c_view || sender.view == c_pic && randomFour.count >= 3 {
setupCardWrite(user: randomFour[2])
} else if sender.view == d_view || sender.view == d_pic && randomFour.count >= 4 {
setupCardWrite(user: randomFour[3])
}
}
As you can see, I check that the count is greater than a certain value, but then I still sometimes receive this error:
Thread 1: Fatal error: Index out of range
And when inspecting I see:
randomFour = ([Compliments.User]) 0 values
How can I make sure that the users have been loaded properly?
ios arrays swift null indexoutofrangeexception
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
add a comment |
I have a JSON get request where I retrieve information about four users and then load four views with their pictures, names, etc.
I also have a function where the user can tap on those views and view more information about them.
However, I need to make sure that the array (randomFour) containing the four users contains actual information for the view they are selecting and is not nil.
I attempted to do this by counting the indexes of the array, but for some reason it isn't preventing it from going through and then crashes because the values are nil.
@objc func loadWriteView(sender: UITapGestureRecognizer) {
if sender.view == a_view || sender.view == a_pic && randomFour.count >= 1 {
setupCardWrite(user: randomFour[0])
} else if sender.view == b_view || sender.view == b_pic && randomFour.count >= 2 {
setupCardWrite(user: randomFour[1])
} else if sender.view == c_view || sender.view == c_pic && randomFour.count >= 3 {
setupCardWrite(user: randomFour[2])
} else if sender.view == d_view || sender.view == d_pic && randomFour.count >= 4 {
setupCardWrite(user: randomFour[3])
}
}
As you can see, I check that the count is greater than a certain value, but then I still sometimes receive this error:
Thread 1: Fatal error: Index out of range
And when inspecting I see:
randomFour = ([Compliments.User]) 0 values
How can I make sure that the users have been loaded properly?
ios arrays swift null indexoutofrangeexception
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
The answer to this post shows a solution to ensure array indexes are not out of range: stackoverflow.com/questions/25329186/…
– Norman
Nov 17 '18 at 0:55
add a comment |
I have a JSON get request where I retrieve information about four users and then load four views with their pictures, names, etc.
I also have a function where the user can tap on those views and view more information about them.
However, I need to make sure that the array (randomFour) containing the four users contains actual information for the view they are selecting and is not nil.
I attempted to do this by counting the indexes of the array, but for some reason it isn't preventing it from going through and then crashes because the values are nil.
@objc func loadWriteView(sender: UITapGestureRecognizer) {
if sender.view == a_view || sender.view == a_pic && randomFour.count >= 1 {
setupCardWrite(user: randomFour[0])
} else if sender.view == b_view || sender.view == b_pic && randomFour.count >= 2 {
setupCardWrite(user: randomFour[1])
} else if sender.view == c_view || sender.view == c_pic && randomFour.count >= 3 {
setupCardWrite(user: randomFour[2])
} else if sender.view == d_view || sender.view == d_pic && randomFour.count >= 4 {
setupCardWrite(user: randomFour[3])
}
}
As you can see, I check that the count is greater than a certain value, but then I still sometimes receive this error:
Thread 1: Fatal error: Index out of range
And when inspecting I see:
randomFour = ([Compliments.User]) 0 values
How can I make sure that the users have been loaded properly?
ios arrays swift null indexoutofrangeexception
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
I have a JSON get request where I retrieve information about four users and then load four views with their pictures, names, etc.
I also have a function where the user can tap on those views and view more information about them.
However, I need to make sure that the array (randomFour) containing the four users contains actual information for the view they are selecting and is not nil.
I attempted to do this by counting the indexes of the array, but for some reason it isn't preventing it from going through and then crashes because the values are nil.
@objc func loadWriteView(sender: UITapGestureRecognizer) {
if sender.view == a_view || sender.view == a_pic && randomFour.count >= 1 {
setupCardWrite(user: randomFour[0])
} else if sender.view == b_view || sender.view == b_pic && randomFour.count >= 2 {
setupCardWrite(user: randomFour[1])
} else if sender.view == c_view || sender.view == c_pic && randomFour.count >= 3 {
setupCardWrite(user: randomFour[2])
} else if sender.view == d_view || sender.view == d_pic && randomFour.count >= 4 {
setupCardWrite(user: randomFour[3])
}
}
As you can see, I check that the count is greater than a certain value, but then I still sometimes receive this error:
Thread 1: Fatal error: Index out of range
And when inspecting I see:
randomFour = ([Compliments.User]) 0 values
How can I make sure that the users have been loaded properly?
ios arrays swift null indexoutofrangeexception
ios arrays swift null indexoutofrangeexception
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
asked Nov 16 '18 at 21:47
Levi KLevi K
7117
7117
The answer to this post shows a solution to ensure array indexes are not out of range: stackoverflow.com/questions/25329186/…
– Norman
Nov 17 '18 at 0:55
add a comment |
The answer to this post shows a solution to ensure array indexes are not out of range: stackoverflow.com/questions/25329186/…
– Norman
Nov 17 '18 at 0:55
The answer to this post shows a solution to ensure array indexes are not out of range: stackoverflow.com/questions/25329186/…
– Norman
Nov 17 '18 at 0:55
The answer to this post shows a solution to ensure array indexes are not out of range: stackoverflow.com/questions/25329186/…
– Norman
Nov 17 '18 at 0:55
add a comment |
1 Answer
1
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oldest
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Please try using brackets around the first two conditions
if (sender.view == a_view || sender.view == a_pic) && randomFour.count >= 1
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
1
@LeviK Without the parentheses, this particular statement is treated as if you wroteif sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1)which is clearly not what you intended. Whenever you have a mix of||and&&in an expression, always use parentheses to avoid any ambiguity.
– rmaddy
Nov 16 '18 at 22:46
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
add a comment |
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Please try using brackets around the first two conditions
if (sender.view == a_view || sender.view == a_pic) && randomFour.count >= 1
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
1
@LeviK Without the parentheses, this particular statement is treated as if you wroteif sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1)which is clearly not what you intended. Whenever you have a mix of||and&&in an expression, always use parentheses to avoid any ambiguity.
– rmaddy
Nov 16 '18 at 22:46
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
add a comment |
Please try using brackets around the first two conditions
if (sender.view == a_view || sender.view == a_pic) && randomFour.count >= 1
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
1
@LeviK Without the parentheses, this particular statement is treated as if you wroteif sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1)which is clearly not what you intended. Whenever you have a mix of||and&&in an expression, always use parentheses to avoid any ambiguity.
– rmaddy
Nov 16 '18 at 22:46
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
add a comment |
Please try using brackets around the first two conditions
if (sender.view == a_view || sender.view == a_pic) && randomFour.count >= 1
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
Please try using brackets around the first two conditions
if (sender.view == a_view || sender.view == a_pic) && randomFour.count >= 1
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
answered Nov 16 '18 at 21:55
Sophie S.Sophie S.
51110
51110
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
1
@LeviK Without the parentheses, this particular statement is treated as if you wroteif sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1)which is clearly not what you intended. Whenever you have a mix of||and&&in an expression, always use parentheses to avoid any ambiguity.
– rmaddy
Nov 16 '18 at 22:46
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
add a comment |
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
1
@LeviK Without the parentheses, this particular statement is treated as if you wroteif sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1)which is clearly not what you intended. Whenever you have a mix of||and&&in an expression, always use parentheses to avoid any ambiguity.
– rmaddy
Nov 16 '18 at 22:46
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
Ok, thank you. I will try that. Shouldn't the brackets have no effect though?
– Levi K
Nov 16 '18 at 22:15
1
1
@LeviK Without the parentheses, this particular statement is treated as if you wrote
if sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1) which is clearly not what you intended. Whenever you have a mix of || and && in an expression, always use parentheses to avoid any ambiguity.– rmaddy
Nov 16 '18 at 22:46
@LeviK Without the parentheses, this particular statement is treated as if you wrote
if sender.view == a_view || (sender.view == a_pic && randomFour.count >= 1) which is clearly not what you intended. Whenever you have a mix of || and && in an expression, always use parentheses to avoid any ambiguity.– rmaddy
Nov 16 '18 at 22:46
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
Got it, thank you so much! It usually takes a few hundred tests to get the problem, so if it ever happens again, I will let you know. Thank you so much for your time and efforts, I will mark this correct unless it ends up not working
– Levi K
Nov 16 '18 at 23:23
add a comment |
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The answer to this post shows a solution to ensure array indexes are not out of range: stackoverflow.com/questions/25329186/…
– Norman
Nov 17 '18 at 0:55