[C language] explain the usage of memset() function in detail

1、memset Function introduction

void * __cdecl memset(void *_Dst,int _Val,size_t _Size);

explain ： Copy characters _Val（ An unsigned character ） To parameter _Dst  The front of the string to which it refers _Size  Characters .memset The function is an initialization function , You can initialize a continuous memory to a certain value .

effect ： Is to fill a given value in a memory block , It is the fastest way to clear a large structure or array .

The header file ：#include <string.h>

Be careful ：memset Functions are assigned by bytes .

2、 Program instance

Clear large structures or arrays

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

//  Structure  People
typedef struct {
    int m;
    int n;
    int z;
}People;

int main(){
    //  Allocate memory space 
    People *peo = (People*)malloc(sizeof(People));

    //  Make a continuous memory initialize a specific value 
    memset(peo,0, sizeof(People));

    printf("m = %d\n",peo->m);
    printf("n = %d\n",peo->n);
    printf("z &