- //strlen - calculate the length of a string//
- #include <stdio.h>
- int strlens(const char *s);
- char strcats(char *dest, const char *src);
- #define NUM 100
- int main(void)
- {
- char c[NUM];
- char *s;
- s = c;
- printf("Please input:");
- gets(s);
- printf("The length of string is %d.\n",strlens(s));
- return 0;
- }
- int strlens(const char *s)
- {
- int i;
- for (i = 0; *s++ != '\0'; i++);
- return i;
- }
- /* concatenate two strings */
- #include <stdio.h>
- char* strcats(char *dest,const char *src);
- int main(void)
- {
- char a[100],b[100];
- char *m,*n;
- m = a;
- n = b;
- printf("Please input:");
- gets(m);
- printf("Please input:");
- gets(n);
- puts(m);
- puts(n);
- strcats(m,n);
- puts(m) ;
- return 0;
- }
- char* strcats(char *dest,const char *src)
- {
- int i = 0;
- char *ch = dest;
- while (*ch) {
- ch++;
- }
- while (*ch++ = *src++);
- return (dest);
- }
- #include <stdio.h>
- char* strcpys(char * dest,const char * src);
- int main(void)
- {
- char c[100],d[100], *s,*q;
- s = c;
- q = d;
- printf("Please input:");
- gets(s);
- printf("Please input:");
- gets(q);
- strcpys(s,q);
- puts(s);
- // puts(q);
- return 0;
- }
- char* strcpys(char * dest,const char * src)
- {
- while (*src != '\0') {
- *dest++ = *src++;
- }
- *dest = '\0';
- return dest;
- }
- #include <stdio.h>
- strcmps(char *s, char *t);
- int main(void)
- {
- int N;
- char a[100],b[100],*s,*q;
- s = a;
- q = b;
- printf("Please input:");
- gets(s);
- printf("Please input:");
- gets(q);
- N = strcmps(s,q);
- printf("%d\n",N);
- return 0;
- }
- strcmps(char *s, char *t)
- {
- while(*s==*t)
- {
- if(*s !='\0')
- return 0;
- ++s; ++t;
- }
- return (*s - *t);
- }
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