int 表示数据类型为整数的变量。sizeof(int) 返回用于存储整数的字节数。 int* 表示指向数据类型为整数的变量的指针。sizeof(int*) 返回用于存储指针的字节数。 由于sizeof 运算符返回数据类型的大小或我们传递给它的参数。因此,在将 (int *) 的变量传递给它之后它应该返回的值: 由于int* 指向一个地址位置,因...
C语言sizeof——平常所忽略的细节 本文章不从头说起sizeof,只讨论sizeof的一些细节问题。 今天做了一道面试题,是关于sizeof的,题如下: int a = 3; int b; b = sizeof(++a + ++a); printf(“%d, %d”, a, b); (对于64或32位机)答案: 3, 4 为什么?为啥a是3?它不是自加了两次吗? 本人...
In case you perform an addition operation on two integers and save the outcome in a particular data type (long), there is a possibility of overflow if this data type (long) has the same size as the other data type (int). This issue arises due to the absence of an assured size for ...
需要Sizeof 1. 找出数组中元素的数量。 Sizeof 可用于自动计算数组元素的数量。让我们看看例子: C实现 #include<stdio.h> intmain() { intarr[]={1,2,3,4,7,98,0,12,35,99,14}; printf("Number of elements:%lu ",sizeof(arr)/sizeof(arr[0])); return0; } C++ 实现 #include<iostream> us...
};intmain() {structB b; printf("Size of struct B: %lu\n",sizeof(structB)); printf("Size of object b: %lu\n",sizeof(b));return0; } Output: Size of struct B: 24 Size of object b: 24 In the above structure, we find that the size is 24 Bytes though the same data members...
sizeof( i ); // ok sizeof i; // ok sizeof( int ); // ok sizeof int; // error 既然写法3可以用写法1代替,为求形式统一以及减少我们大脑的负担,第3种写法,忘 掉它吧! 实际上,sizeof计算对象的大小也是转换成对对象类型的计算,也就是说,同种类型的 ...
2.sizeof真正计算的时间是编译期,由编译器把sizeof的结果计算好放入相对应的位址,过量使用sizeof运算符也不会对系统性能产生不利影响。 考虑如下代码: //code #1 constsize_t val=4; intarr[val]; //code #2 intarr[sizeof(int)]; 如果sizeof(int)的结是为4那么上面的code #1和code #2几乎没有差别...
在Pascal 语言与C语言中，对 sizeof() 的处理都是在编译阶段进行。相关定义 sizeof是C/C++中的一个操作符（operator），简单的说其作用就是返回一个对象或者类型所占的内存字节数。MSDN上的解释为：The sizeof keyword gives the amount of storage, in bytes, associated with a variable or a ...
How do I print the size of int in C? Question: I consistently receive a warning while attempting to compile the following on RHEL 5.6, 64-bit. In line 7 of var.c, there is a warning indicating that the format '%d' expects an int type for the second argument, but instead it is of...
We saw that compiler keeps aligning greedily & that's why it aligned char b of base class member & char d, which is its member, in the same row. When it tried to align int c, it could not as only 2 bytes were left. But instead of int, if it was char only ...