Displaying a float to a number of decimals

Seem开发者_StackOverflow中文版s an easy question. And it can be done using the following format "%.#f". Replacing # with a number will give you that number of decimals. But what if you want to pass in an NSInteger variable to specify the value of #?

I am trying to display a label containing a price with the number of decimals the user had previously specified. Is this possible?

The following code is what a want to change. I want to substitute the hardcoded number (in this case "4") with a variable of type NSInteger.

lblPrice.text = [NSString stringWithFormat:@"%.4f",val_stdPrice];

Any help in this matter would be greatly appreciated.

Construct the formatting string dynamically:

NSString *fmtString = [NSString stringWithFormat:@"%%.%df", 17];
NSString *resultString = [NSString stringWithFormat:fmtString, 1.337f];
NSLog (resultString);

Retrieve the Integer and append it to the string to match the format. Then use the string as a parameter.