1.特定位置替换:

NSMutableString *tempString = [inputText mutableCopy];
NSRange range = [inputText rangeOfString:@":"];
if (range.length != 0) {
[tempString replaceCharactersInRange:range withString:@""];
}

 

2.全部替换:

NSMutableString *tempString = [inputText mutableCopy];
NSRange range = NSMakeRange(0, [tempString length]);
[tempString replaceOccurrencesOfString:@":" withString:@"" options:NSCaseInsensitiveSearch range:range];