C语言内存分配(九)

#include <stdlib.h> //malloc free
void malAndFree();
void greatMal(int num);

int main(int argc, const char * argv[]) {
    
    
    long long *i;
    long long b = 11111111111111;
    i = (long long*)malloc(sizeof(long long)*3);
    *i = b;
    
    double a = 334.55f;
    
    double *d = &a;
    
    malAndFree();

    return 0;
}


void malAndFree()
{
    //这种
    double g[2000];
    printf("g内存大小 = %ld",sizeof(g)); //16000bytes
    
    
    greatMal(2000);
    
}


void greatMal(int num)
{
    //用malloc 申请的内存空间，在函数结束前进行 free，否则函数只是自动清空temp指针，而没有清空temp所指向的内存,达到上内存警告上限就会溢出
    double *temp = malloc(sizeof(double)*num);
    printf("temp内存大小 = %ld",sizeof(temp)); //16000bytes

    
    double *temp2 = (double*)calloc(2000, sizeof(double));
    printf("temp2内存大小 = %ld",sizeof(temp)); //16000bytes

    free(temp);
    free(temp2);
}