C语言代码练习（test_1_19）

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>int num = 10;
int main()
{int a;int b;//从键盘读入数据 ： 格式化  &a//scanf("%d%d", &a,&b);//printf("a = %d , b = %d\n", a,b);//局部变量 优先原则 //多组输入 scanf库函数-》返回值是整数 EOF/-1 ：都代表读取完了 while (scanf("%d%d", &a, &b) != EOF){printf("a = %d , b = %d\n", a, b);//局部变量 优先原则 }return 0;
}int main()
{//整型数组int arr[10] = {1,2,3,4,5,6};//字符数组char arr2[] = {'b','i','t'};printf("%d\n", strlen(arr2));//在内存当中 找  看哪里有\0 计算就终止了 printf("%s\n",arr2);printf("%d\n",'\60');//求字符串长度的(字符的个数)！库函数 -》 导入头文件//printf("%d\n", strlen("abcd\0opk"));//不包含\0 printf("%d\n", strlen("c:\test\121"));int a = 31;switch (a){default://默认的 printf("gaobo is cool? \n");break;case 2:printf("gaobo is very cool!\n");break;case 3:printf("gaobo is very very cool!\n");break;case 1:printf("gaobo is cool!\n");break;}return 0;
}

、test_1_19

#include<stdio.h>
int main()
{printf("hahah\n");return 0;
}