book@100ask:~/C_coding/CH01$ cat char1.c
#include <stdio.h>
#include <stdlib.h>
#define N 32
int main()
{
char str[N] = {'a','b','c'};
int i;
scanf("%s",str);
printf("%s\n",str);
exit(0);
}
book@100ask:~/C_coding/CH01$ make char1
cc char1.c -o char1
book@100ask:~/C_coding/CH01$ ./char1
hello
hello
book@100ask:~/C_coding/CH01$
book@100ask:~/C_coding/CH01$ cat char1.c
#include <stdio.h>
#include <stdlib.h>
#define N 32
int main()
{
char str[N],str1[N],str2[N];
int i;
scanf("%s%s%s",str,str1,str2);
printf("%s\n%s\n%s\n",str,str1,str2);
exit(0);
}
book@100ask:~/C_coding/CH01$ make char1
cc char1.c -o char1
book@100ask:~/C_coding/CH01$ ./char1
hello word chaina
hello
word
chaina
book@100ask:~/C_coding/CH01$ ./char1
hello he2 he3 he4 he5 he6 //当有多个输出时，自动只赋值前三个串
hello
he2
he3字符串常用函数：
strlen & sizeof
book@100ask:~/C_coding/CH01$ cat char2.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// strlen & sizeof
#define N 32
int main()
{
char str[] = "hello";
printf("%d\n",strlen(str)); //strlen显示字符的实际长度，此处hello包含5个字符，故显示5
printf("%d\n",sizeof(str)); //sizeof打印字符串的总长度，包括尾零，此处hello包括尾零共6
exit(0);
}
book@100ask:~/C_coding/CH01$ make char2
cc char2.c -o char2
book@100ask:~/C_coding/CH01$ ./char2
5
6book@100ask:~/C_coding/CH01$ cat char2.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 32
int main()
{
char str[] = "hello\0abc";
printf("%d\n",strlen(str)); //strlen以\0分割，因此此处打印5
printf("%d\n",sizeof(str)); //sizeof会将中间的\0也算进去，算一个空间，hello + \0 + abc + \0 = 10个字符空间
exit(0);
}
book@100ask:~/C_coding/CH01$ ./char2
5
10
strcpy & strncpy
book@100ask:~/C_coding/CH01$ cat strcp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 32
int main()
{
char str[] = "hello\0abc"; //给字符串数组str赋初值
strcpy(str,"abcde"); //将abcde copy给字符串数组str
puts(str); //将strcp运算后的字符串str输出
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcp
cc strcp.c -o strcp
book@100ask:~/C_coding/CH01$ ./strcp
abcdebook@100ask:~/C_coding/CH01$ cat strcp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 32
int main()
{
char str[3]; //初始化，定义字符串数组的长度为3
strcpy(str,"abcde"); //当copy的内容超过容量，仍然可以赋值，即字符串数组长度的定义在此处失效
puts(str);
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcp
cc strcp.c -o strcp
book@100ask:~/C_coding/CH01$ ./strcp
abcde
book@100ask:~/C_coding/CH01$ cat strncp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE];
strncpy(str,"abcde",STRSIZE); //限定copy的最大字符数为STRSIZE
puts(str);
exit(0);
}
book@100ask:~/C_coding/CH01$ make strncp
cc strncp.c -o strncp
book@100ask:~/C_coding/CH01$ ./strncp
abcdebook@100ask:~/C_coding/CH01$ cat strncp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 3
int main()
{
char str[STRSIZE];
strncpy(str,"abcde",STRSIZE); //当限定copy的最大字符数为STRSIZE=3时，最多可被copy3个字符
puts(str);
exit(0);
}
book@100ask:~/C_coding/CH01$ make strncp
cc strncp.c -o strncp
book@100ask:~/C_coding/CH01$ ./strncp
abcstrcat & strncat
book@100ask:~/C_coding/CH01$ cat strcat.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE] = "hello";
strcat(str," "); //strcat负责把不同的字符串连接在一起
strcat(str,"world!");
puts(str);
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcat
cc strcat.c -o strcat
book@100ask:~/C_coding/CH01$ ./strcat
hello world!
book@100ask:~/C_coding/CH01$ cat strnc
strncat strncat.c strncp strncp.c
book@100ask:~/C_coding/CH01$ cat strncat.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 5
int main()
{
char str[STRSIZE] = "hello";
strncat(str," ",STRSIZE);
strncat(str,"world!",STRSIZE); //限定一次连接的最大长度为STRSIZE
puts(str);
exit(0);
}
book@100ask:~/C_coding/CH01$ make strncat
cc strncat.c -o strncat
book@100ask:~/C_coding/CH01$ ./strncat
hello worldstrcmp & strncmp
book@100ask:~/C_coding/CH01$ cat strcmp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE] = "hello";
char str1[STRSIZE] = "world";
printf("%d\n",strcmp(str,str1)); //对比，左边的字符串（从第一个字符开始比较，大于则返回整数，小于返回负数）
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcmp
cc strcmp.c -o strcmp
book@100ask:~/C_coding/CH01$ ./strcmp
-15book@100ask:~/C_coding/CH01$ cat strcmp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE] = "hello";
char str1[STRSIZE] = "aworld";
printf("%d\n",strcmp(str,str1));
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcmp
cc strcmp.c -o strcmp
book@100ask:~/C_coding/CH01$ ./strcmp
7
book@100ask:~/C_coding/CH01$ cat strcmp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE] = "hello";
char str1[STRSIZE] = "hello";
printf("%d\n",strcmp(str,str1));
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcmp
cc strcmp.c -o strcmp
book@100ask:~/C_coding/CH01$ ./strcmp
0book@100ask:~/C_coding/CH01$ cat strcmp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE] = "hello";
char str1[STRSIZE] = "helloa";
printf("%d\n",strcmp(str,str1));
exit(0);
}
book@100ask:~/C_coding/CH01$ make strcmp
cc strcmp.c -o strcmp
book@100ask:~/C_coding/CH01$ ./strcmp
-97
book@100ask:~/C_coding/CH01$ cat strncmp.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STRSIZE 32
int main()
{
char str[STRSIZE] = "hello";
char str1[STRSIZE] = "helloa";
printf("%d\n",strncmp(str,str1,5)); //strncmp设定对比的字符数为前n个
exit(0);
}
book@100ask:~/C_coding/CH01$ make strncmp
cc strncmp.c -o strncmp
book@100ask:~/C_coding/CH01$ ./strncmp
0