oc基本数据类型例子

        //基本数据类型
        int i = 10;
        float f = 3.1567f;
        double d = 3.123e+11;
        char c = ‘x‘;

        NSLog(@"i:%d",i);
        NSLog(@"f:%.2f",f);//打印两位小数
        NSLog(@"d:%e",d);
        NSLog(@"c:%c",c);

        //打印x的ASCII值
        NSLog(@"x ascii:%d",c);  //120

        //打印数据类型所占用的字节
        NSLog(@"i sizeof:%ld",sizeof(i));
        NSLog(@"f sizeof:%ld",sizeof(f));
        NSLog(@"d sizeof:%ld",sizeof(d));
        NSLog(@"c sizeof:%ld",sizeof(c));