Comparing 2 strings in Objective-C

Question

I have a NSTask of which the output is stored in an NSData object. From this I get a string via

NSString *outputString = [[NSString alloc] initWithData:outputData encoding:NSUTF8StringEncoding];

Now I can NSLog this string and then compare it via [outputString isEqualToString:@"NSLogged String"]. The result is that the two strings are not identical. Why is that? I played with the encoding but this does not seem to be the problem.

@AnoopVaidya This is what I copied from Xcode's output terminal: /usr/bin/python — DaPhil, Mar 10 '14 at 08:13
If your copied string is `/usr/bin/python` then you should use `[outputString isEqualToString:@"/usr/bin/python"]` — Anoop Vaidya, Mar 10 '14 at 08:14
@AnoopVaidya Just put in a placeholder in the question and not the exact string. This is of course what I do. — DaPhil, Mar 10 '14 at 08:16
@DaPhil: Perhaps the string read from the task contains a trailing newline? - Can you show the output of `NSLog(@"output='%@', outputString)` ? — Martin R, Mar 10 '14 at 08:18
a little correction in *Martin R*'s comment, `NSLog(@"output='%@'", outputString)`. Added closing `"`. — Anoop Vaidya, Mar 10 '14 at 08:22
@Flovdis: Reading from the process started by NSTask is probably done with a NSFileHandle, and that returns the data as NSData objects. — Martin R, Mar 10 '14 at 08:57

score 1 · Accepted Answer · answered Mar 10 '14 at 08:28

The output from your tool contains a trailing newline character. So either compare against "yourExpectedString\n" or use something like

outputString = [outputString stringByTrimmingCharactersInSet:[NSCharacterSet newlineCharacterSet];

to remove the newline characters.

Comparing 2 strings in Objective-C

1 Answers1