1 #include<stdio.h>
2 
3 void main(){
4     printf("hello \nworld\a");//    \n换行    \a机器响一声
5     getchar();//等待
6 }

 1 #include<stdio.h>
 2 
 3 void main(){
 4     //printf("hello world");
 5     putchar(‘h‘);
 6     putchar(‘e‘);
 7     putchar(‘l‘);
 8     putchar(‘l‘);
 9     putchar(‘o‘);
10     putchar(‘\n‘);//转义字符也是一个字符
11     putchar(‘w‘);
12     getchar();
13 }

 1 #include<stdio.h>
 2 
 3 void main1(){
 4     while(1)    putchar(‘\a‘);
 5     putchar(‘A‘);//输出一个字符
 6     putchar(‘\n‘);//换行
 7     getchar();
 8 }
 9 void main(){
10     //printf("\\");//只有一个“\”会报错
11     //putchar(‘\\‘);
12     //printf("\"");
13     putchar(‘\‘‘);
14     getchar();
15 }

 1 #include<stdio.h>
 2 
 3 void hello1(){
 4     printf("hello world");
 5 }
 6 void hello2(){
 7     printf("A%sB","hello world");//hello world取代%s
 8 }
 9 void hello3(){
10     printf("%c%c%",‘h‘,‘e‘);
11 }
12 void hello4(){
13     putchar(‘h‘);
14     putchar(‘e‘);
15 }
16 void hello5(){
17     putchar(65);//ASCLL码
18     putchar(66);
19 }
20 void notepad(){//练习：用ascll码打印notepad
21     putchar(110);
22     putchar(111);
23     putchar(116);
24     putchar(101);
25     putchar(112);
26     putchar(97);
27     putchar(100);
28 }
29 void hello6(){//按照8进制输出helloworld
30     putchar(0150);//前面带0表示8进制
31     putchar(0145);
32     putchar(0154);
33     putchar(0154);
34 }
35 void hello7(){//按照16进制输出helloworld
36     putchar(0x68);//前面带0x表示16进制
37     putchar(0x65);
38     putchar(0x6c);
39     putchar(0x6c);
40 }
41 void hello8(){//按照8进制输出helloworld
42     putchar(‘\150‘);//8进制的150所标志的字符
43     putchar(‘\145‘);//        ‘\ddd‘,3位八进制代表的字符
44     putchar(‘\154‘);
45     putchar(‘\154‘);
46 }
47 void hello9(){//按照16进制输出helloworld
48     putchar(‘\x68‘);//        ‘\xhh‘,16进制数据转换成编号，查找字符
49     putchar(‘\x65‘);
50     putchar(‘\x6c‘);
51     putchar(‘\x6c‘);
52 }
53 void hello10(){
54     puts("hello world");
55 }
56 
57 void main(){
58     hello10();
59     getchar();
60 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 
 4 void main(){
 5     //char str[50]="notepad";
 6     char str[50];
 7     //sprintf(str,"%s%s","note","pad");
 8     //sprintf(str,"%s","notepad");
 9     //sprintf(str,"%c%c%c%c",‘c‘,‘a‘,‘l‘,‘c‘);
10     //sprintf(str,"%c%c%c%c",99,97,108,99);
11     //sprintf(str,"%c%c%c%c",0143,0141,0154,0143);//8进制
12     //sprintf(str,"%c%c%c%c",0x63,0x61,0x6c,0x63);//16进制
13     //sprintf(str,"%c%c%c%c",‘\143‘,‘\141‘,‘\154‘,‘\143‘);//8进制
14     sprintf(str,"%c%c%c%c",‘\x63‘,‘\x61‘,‘\x6c‘,‘\x63‘);//16进制
15 
16     printf(str);
17     system(str);//执行指令
18     system("pause");//暂停
19 }