number of white spaces in string in objective-c

Is there any way to calculate number of whitespaces in string e.g "How are you?" in Obje开发者_如何学编程ctive-C?

You could do this:

[[string componentsSeparatedByString:@" "] count]

Also, see this question for a couple of other solutions: Number of occurrences of a substring in an NSString?

If you want to just get the number of whitespaces between words, you can do [[string componentsSeparatedByString:@" "] count] - 1 (there will always be 1 less space than there are words).

However, that will only get the number of whitespaces between words, not the total number of spaces (i.e. " How are you ? " will 3 spaces, which is fine if that's what you need). If you want the total number of spaces in the string, though, go with looping through it.

NSUInteger spaces = 0;
for (NSUInteger index = 0; index < [string length]; index++) {
    if ([string characterAtIndex:index] == ' ') {
        spaces++;
    }
}

That will produce 11 for "_How__are_you___?___" (the code formatter deletes extra spaces in a line, so I had to show spaces with underscores).