IOS字符串的处理例子

NSMutableString *string = [NSMutableString stringWithFormat:@"age is %i.",28];

[string setString:@"123"];

[string appendString:@"456"];

[string appendFormat:@"age is %i.",29];

NSLog(@"afterAppend:%@",string);

[string setString:@"123456"];

NSRange range =[string rangeOfString:@"345"];

[string replaceCharactersInRange:range withString:@"abc"];

NSLog(@"afterreplace:%@",string);