字符串长度: #include<stdio.h> #include<stdlib.h> #include<assert.h> int my_strlen(const char *s) { assert(s); int n=0; while(*s) { n++; s++; } return n; } int main() { char s[]="abcedf"; printf("%d",my_strlen(s)); system("pause"); return 0; } 字符串复制: #include<stdio.h> #include<stdlib.h> #include<assert.h> char *my_strcpy(char *s,const char *c) { assert(s); assert(c); char *q=s; while(*s++=*c++) { ; } return q; } int main() { char s[10]="abced"; char c[]="aegdhj"; printf("%s",my_strcpy(s,c)); system("pause"); return 0; } 字符串比较: #include<stdio.h> #include<stdlib.h> #include<assert.h> int my_strcmp(const char *s,const char *c) { assert(s); assert(c); while(*s++==*c++) { if(*s) { return 0; } } return *s-*c; } int main() { char s[10]="abced"; char c[]="aegdhj"; if(my_strcmp(s,c)) printf("s字符串大"); else if(my_strcmp==0) { printf("字符串一样大"); } else printf("c字符串大"); system("pause"); return 0; } 字符串连接: #include<stdio.h> #include<stdlib.h> #include<assert.h> char *my_strcat(char *s,const char *c) { assert(s); assert(c); char *q=s; while(*s) { s++; } while(*s++=*c++) { ; } return q; } int main() { char s[20]="abced"; char c[]="aegdhj"; printf("%s",my_strcat(s,c)); system("pause"); return 0; }
时间: 2024-12-15 04:20:49