对应的英文是倒过来的 pointer to const。 指针常量,就是指针的常量,指针本身为常量,指向不可更改。对应的英文是倒过来的 const pointer。 用英文理解会更简单一点。 英文记忆法 将程序由后往前念 将* 替换成自然语言 pointer to 将变量后面加上 is a const int p = 3; // p is a int const // 例如...
Another common issue while using theconstqualifier with pointers is non-const pointers’ assignment to the pointers that point to the read-only objects. Notice that, there’s a new non-const variablenumber2initialized in the next code example, and thec_ptrthat was declared as a pointer tocons...
Here, u is a pointer that can point to a const int type variable. We can also write it like, char const* v; 1. still it has the same meaning. In this case also, v is a pointer to an char which is of ...
If theconstlocates the right of the*, it means that the const keyword modifies the datap, i.e. a constant pointer. In addition,constcan also collocates with C++ reference. But there is a litter difference between them. That is because the difference between pointer and reference, which is ...
cp is a const pointer to char. pc2 is a pointer to const char. 用法3:const修饰函数传入参数 将函数传入参数声明为const,以指明使用这种参数仅仅是为了效率的原因,而不是想让调用函数能够修改对象的值。同理,将指针参数声明为const,函数将不修改由这个参数所指的对象。
// constant_values4.cpp#include<stdio.h>intmain(){constchar*mybuf ="test";char*yourbuf ="test2"; printf_s("%s\n", mybuf);constchar*bptr = mybuf;// Pointer to constant dataprintf_s("%s\n", bptr);// *bptr = 'a'; // Error} ...
让我们思考一个最简单的例子,曾经我以为这个例子中的const能够加快C代码运行速度。首先,假设我们有如下两个函数声明: void func(int *x); void constFunc(const int *x); 然后,假设我们有如下两种写法的代码: void byArg(int *x) { printf("%d\\n", *x); ...
指向常量的指针(pointer to const)不能改变其所指对象的值。要想存放常量对象的地址,只能使用☝常量的指针。 /***/ 指向常量的指针也没有规定其所🈯️的对象必须是一个...
Sometimes we may want that a function should not modify the value of a parameter passed to it, either directly within that function or indirectly in some other function called form it. This can be achieved using const parameters. Consider, for example, t
3. Using Pointer to Const Variables A const pointer in C++ is a pointer to a memory location whose value cannot be modified by using the pointer to access it. A read-only reference to a variable can be created using a const pointer. Here’s an example: ...