Remove spaces from a string

This can be accomplished with simple string formatting. Here's an example:

NSString *s = @"0800 444 333";
NSString *secondString = [s stringByReplacingOccurrencesOfString:@" " withString:@""];

See the NSString Class Reference for more details and options.

To further simplify, this line can also be written like this:

NSString *s = [@"0800 444 333" stringByReplacingOccurrencesOfString:@" " withString:@""];

if You want to remove white spaces at start and end the you usestringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]string method.

For eg.

NSString *s = @"0800 444 333";
s = [s stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

And for removing all spaces answer by @NSPostWhenIdle is enough.