c语言 13 - 11

1、

#include <stdio.h>

int main(void)
{
    FILE *fp;
    double a[10] = {1.1,2.1,3.1,4.1,5.1,6.1,7.1,8.1,9.1,0.1};
    int i;
    for(i = 0; i < 10; i++)
    {
        printf("a[%d] = %f.\n", i, a[i]);
    }
    
    
    //利用fwrite函数将数组的值导出到tmp.bin二进制文件中 
    if((fp = fopen("tmp.bin", "wb")) == NULL)
        printf("\aFile open failed.\n");
    else
    {
        fwrite(a, sizeof(double), 10, fp);
        fclose(fp);
    }
    
    
    //利用fread函数读取二进制we年tem.bin的值，保存至数组b中，然后进行显示。
    double b[10];
    if((fp = fopen("tmp.bin", "rb")) == NULL)
        printf("\aFile open failed.\n");
    else
    {
        fread(b, sizeof(double), 10, fp);
        for(i = 0; i < 10; i++)
        {
            printf("elements from array b: b[%d] = %.2f.\n", i, b[i]);
        }    
        fclose(fp);
    } 
    
    return 0;
}