NSString *name = @"jack";
NSString *str = [NSString stringWithFormat:@"My age is %d and no is %d and name is %@", age, no, name];
NSLog(@"我的名字是:%@", name); // 输出:我的名字是:jack
    NSString *str2 = @"哈哈jack";
    
    int size = [str2 length];
    
    NSLog(@"%d", size); // 输出: 6
原文:http://www.cnblogs.com/unique-ios/p/4328806.html