NSString stringWithFormat adding a percent

Question

How can I add a percent to my stringWithFormat function? For example, I'd like to have the following:

float someFloat = 40.233f;
NSString *str = [NSString stringWithFormat:@"%.02f%",someFloat];

This should cause the string to be:

40.23%

But it is not the case. How can I achieve this?

Solution 1

% being the character beginning printf-style formats, it simply needs to be doubled:

float someFloat = 40.233f;
NSString *str = [NSString stringWithFormat:@"%.02f%%",someFloat];

Solution 2

The escape code for a percent sign is “%%”, so your code would look like this

[NSString stringWithFormat:@"%d%%", someDigit];

This is also true for NSLog() and printf() formats.

Cited from How to add percent sign to NSString.