Question

I’ve got some NSString equal @"1234567.89". I have to make floatValue from this string. When I called [myString floatValue] then this float is equal 1234567.875000. How to keep before this? I want have floatValue equal 1234567.89000.

Thank you for help.

Answer 1

The problem is that a float can’t represent a number that large with the precision you’re looking for. Try using a double instead, and retrieve it using [myString doubleValue]. The small example program below demonstrates this:

#import <Foundation/Foundation.h>
int main(int argc, char *argv[]) {
    @autoreleasepool {
        NSString *myString = @"1234567.89";
        float floatVal = [myString floatValue];
        double doubleVal = [myString doubleValue];
        NSLog(@"String: %@ float: %f double: %f", myString, floatVal, doubleVal);
    }
}

String: 1234567.89 float: 1234567.875000 double: 1234567.890000