What does cum mean in c language

In C language, the "cum" keyword represents the address of a variable in a function and can return the memory address of the variable. Usage includes: following the variable name to return a pointer to the variable. References and manipulations variables, storing the address in a pointer. Use with caution, declare the correct type and avoid pointing to invalid memory.

C language cum

"cum" is a keyword in C language that indicates the address of a variable in a function. It is an operator that returns the memory address of a variable.

usage:

The "cum" operator is followed by a variable name and returns a pointer to the variable. A pointer is a value that stores the memory address of a variable. The address of a variable can be used as a pointer to refer to and manipulate variables.

grammar:

 <code class="c">&variable_name</code>

where variable_name is the variable name to get its address.

Example:

 <code class="c">int x = 10; int *ptr = &x; printf("x 的值：%d\n", x); // 输出：10 printf("x 的地址：%p\n", &x); // 输出：内存地址printf("ptr 指向的值：%d\n", *ptr); // 输出：10 *ptr = 20; printf("更改后的x 的值：%d\n", x); // 输出：20</code>

In this example, the "cum" operator is used to get the address of x variable and store it in the pointer ptr . Then, the value of x can be referenced and modified using ptr .

Need to note:

• The "cum" operator returns the address of the variable, not the value of the variable itself.
• The pointer must be declared first to point to the correct type, otherwise an error will be generated.
• If the pointer points to invalid memory, it may cause the program to crash.

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