使用教材

《“笨办法” 学C语言（Learn C The Hard Way）》
https://www.jianshu.com/p/b0631208a794

ex11.c

#include <stdio.h>

int main(int argc,char *argv[])
{
    int numbers[4] = {0};
    char name[4] = {'a'};

    //first, print them out raw
    printf("numbers: %d %d %d %d\n", numbers[0], numbers[1], numbers[2], numbers[3]);

    printf("name each: %c %c %c %c\n", name[0], name[1], name[2], name[3]);

    printf("name: %s\n", name);

    // set up the numbers
    numbers[0] = 1;
    numbers[1] = 2;
    numbers[2] = 3;
    numbers[3] = 4;

    // set up the name
    name[0] = 'Z';
    name[1] = 'e';
    name[2] = 'd';
    name[3] = '\0';

    // then print them out initialized
    printf("numbers: %d %d %d %d\n", numbers[0], numbers[1], numbers[2], numbers[3]);

    printf("name each: %c %c %c %c\n", name[0], name[1], name[2], name[3]);

    // print the name link a string
    printf("name: %s\n", name);

    // another way for use name
    char *another = "Zed";

    printf("another: %s\n", another);

    printf("another each: %c %c %c %c \n", another[0], another[1], another[2], another[3]);

    return 0;
}

Makefile

CC=clang
CFLAGS=-Wall -g

clean:
    rm -f ex11

run

anno@anno-m:~/Documents/mycode/ex11$ make ex11
clang -Wall -g    ex11.c   -o ex11
anno@anno-m:~/Documents/mycode/ex11$ ./ex11
numbers: 0 0 0 0
name each: a   
name: a
numbers: 1 2 3 4
name each: Z e d 
name: Zed
another: Zed
another each: Z e d  

说明

• 数组如果只初始化了一个元素，剩下的元素会用0来填充；

int numbers[4] = {0};
numbers: 0 0 0 0
第1个0 是初始化的那个元素
剩余3个0是填充的0

char name[4] = {'a'};
name each: a  
填充字符'\0'使得字符串被正确地结束了

• 初始化字符串 以及 输出字符串

char *another = "Zed";

printf("another: %s\n", another);

another: Zed

to-do

code

//to-do-1
    int test_num[3] = {'0'};
    test_num[0] = 'a';
    printf("number %%d : %d\n", test_num[0]);
    printf("number %%c : %c\n", test_num[0]);

    //to-do-2
    char test_name[3] = {};
    test_name[0] = 't';
    printf("char %%d : %d\n", test_name[0]);

    //to-do-3
    char *test_another = "Hello world!";
    printf("%s\n", test_another);

output

number %d : 97
number %c : a
char %d : 116
Hello world!

• C语言中字符char就是一个小整数，%d输出这个整数的值，%c输出这个字符；