Analysis and comparison of * and & operators in C language

In C language, the asterisk (*) operator is used to dereference a pointer variable and obtain the value of the variable pointed to; the address operator (&) is used to obtain the variable address. The specific comparison is as follows: Dereference pointer: *Get address: & pointer multiplication: *Bit operation: &

* and & operator analysis and comparison in C language

In C language, the asterisk (*) operator and the address operator (&) operator are two important operators, which are often used for pointer operations and memory management. This article will deeply analyze their uses and differences, and provide practical cases to illustrate.

The asterisk (*) operator

• The asterisk operator is used to dereference a pointer variable and obtain the value of the variable it points to.
• Syntax: *Pointer variable

• For example:

  • int *ptr = &i;
  • printf("%d", *ptr); //Print the value of i

Address operator (&) operator

• Address operation The operator is used to obtain the address of a variable and returns a pointer to the variable.
• Syntax: &Variable name

• For example:

  • int i = 10;
  • int *ptr = &i;
  • printf("%p", ptr); // Print the address of i

Comparison operator

The following is a comparison of the * and & operators in different scenarios:

Operator	Scenario	Function
*	Dereference pointer	Get the value pointed to the variable
&	Get the address	Get the address of the variable
*	Pointer multiplication	Calculate the size of the memory space pointed by the pointer
&	Bitwise operation (logical AND)	Perform logical AND operation on two integers

Practical Case

The following is a practical case that demonstrates how the * and & operators are used for pointer operations:

#include <stdio.h>

int main() {
    int i = 10;
    int *ptr = &i; // ptr指向i

    // 通过解引用指针获取i的值
    printf("i的值：%d\n", *ptr);

    // 通过取地址获取i的地址
    printf("i的地址：%p\n", &i);

    // 通过指针乘法计算ptr指向的内存空间大小
    int size = sizeof(*ptr);
    printf("ptr指向内存空间大小：%d字节\n", size);

    // 使用指针进行递增
    (*ptr)++; 

    // 打印递增后的i值
    printf("递增后的i：%d\n", i);

    return 0;
}

Output:

i的值：10
i的地址：0x7ffe5247ef4c
ptr指向内存空间大小：4字节
递增后的i：11

The above is the detailed content of Analysis and comparison of * and & operators in C language. For more information, please follow other related articles on the PHP Chinese website!