C language: detailed usage of memset()

1. Introduction to memset()

1.1 Function prototype

void *memset(void *s, int ch, size_t n);

1.2 Parameters

• s -pointer to the memory block.
• ch -the value used for replacement.
• n -the number of bytes to be replaced.

1.3 Function

Replace the n bytes after the current position in s with ch and return s.
The function is to fill a given value in a memory block, which is often used for clearing operations of larger structures and arrays.

1.4 Header files

#include <string.h>

2. Memset() usage

The memset function is often used to clear larger structures and arrays.
The specific code is as follows:

#include <stdio.h>
#include <string.h>	

int main(void)
{
    
    
	char data[7]="memset"; 
	printf("%s\n",data);
	
	memset(data,1,6);//全部置换为整数 
	printf("%d %d %d %d %d %d\n",data[0],data[1],data[2],data[3],data[4],data[5]);
	 
	memset(data,'a',6);//全部置换为字符 
	printf("%s\n",data);
	
	memset(&data[4],1,2);//局部置换
	printf("%d %d %d %d %d %d\n",data[0],data[1],data[2],data[3],data[4],data[5]);
	return 0;
}

The results are as follows:

memset
1 1 1 1 1 1
aaaaaa
97 97 97 97 1 1