/* 1. 求字符串长度函数 */ int myStrlen(char *str) { int cnt = 0; while(*str++ != '\0') { cnt++; } return cnt; } /* 2. 字符串拼接函数 */ char *myStrcat(char *des, char *src) { char *str = des; while(*des != '\0') { des++; } while((*src != '\0') && (*des++ = *src++)); *des = '\0'; return str; } /* 3. 字符串拷贝函数 */ char *mystrcpy(char *des, char *src) { while((*src != '\0') && (*des++ = *src++)); *des = '\0'; return des; } int mystrcmp(char *s,char *t) { while(*s==*t) { if(*s==’\0’) return 0; else s++,t++; } return *s-*t; }