Check if a NSString is empty or only contains whitespace or tabs?

Question

I'm currently using isEqualToString:@"" and it works fine when the textField does have nothing. However, it does not catch the case when the input has only white spaces or tabs. What should I do to make it smarter so that input such as " " will not be allowed.

score 29 · Accepted Answer · answered Oct 24 '13 at 21:31

29

NSCharacterSet *charSet = [NSCharacterSet whitespaceCharacterSet];
NSString *trimmedString = [myString stringByTrimmingCharactersInSet:charSet];
if ([trimmedString isEqualToString:@""]) {
    // it's empty or contains only white spaces
}

answered Oct 24 '13 at 21:31

DrummerB

39,275
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141

score 9 · Answer 2 · answered Oct 24 '13 at 21:32

9

[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]].length > 0

Use this to test if the string contains characters other than whitespace.

answered Oct 24 '13 at 21:32

Léo Natan

56,383
9
144
191

Check if a NSString is empty or only contains whitespace or tabs?

2 Answers2