macOS making backspace button on Xcode

[abcdefg12345]

im trying to make a backspace button for an xcode project but its not working

heres the code for it can anyone edit it to make it work

 

[alexbussman]

A quick and dirty fix to your code would look something like this:

-(IBAction)Back:(id)sender {
    NSString *backspace = [conv_display stringValue];   
    float lengthofstring = backspace.length;
    if (lengthofstring == 0)
        return;

    backspace = [backspace substringToIndex:lengthofstring - 1];
    [conv_display setStringValue:backspace];
}

Reason is that you were thinking you got a NSString in the first line, but you were actually getting a NSTextField.

You would have found this easily if you used the actual class names instead of id for your IBOutlets.
It's always a good idea to avoid id unless you really have a good reason to use it.
Hope this helps you to continue

// Alex

 

[abcdefg12345]

A quick and dirty fix to your code would look something like this:

-(IBAction)Back:(id)sender {
    NSString *backspace = [conv_display stringValue];   
    float lengthofstring = backspace.length;
    if (lengthofstring == 0)
        return;

    backspace = [backspace substringToIndex:lengthofstring - 1];
    [conv_display setStringValue:backspace];
}

Reason is that you were thinking you got a NSString in the first line, but you were actually getting a NSTextField.

You would have found this easily if you used the actual class names instead of id for your IBOutlets.
It's always a good idea to avoid id unless you really have a good reason to use it.
Hope this helps you to continue

// Alex

thanks a lot I tried it and it worked

 

[Henley]

A quick and dirty fix to your code would look something like this:

-(IBAction)Back:(id)sender {
    NSString *backspace = [conv_display stringValue];   
    float lengthofstring = backspace.length;
    if (lengthofstring == 0)
        return;

    backspace = [backspace substringToIndex:lengthofstring - 1];
    [conv_display setStringValue:backspace];
}

Reason is that you were thinking you got a NSString in the first line, but you were actually getting a NSTextField.

You would have found this easily if you used the actual class names instead of id for your IBOutlets.
It's always a good idea to avoid id unless you really have a good reason to use it.
Hope this helps you to continue

// Alex

Hey where would you implement this is in the main file or the header file?