c语言大小写字母转换

#define_CRT_SECURE_NO_WARNINGS#include<stdlib.h>#include<string.h>#include<stdio.h>#include<windows.h>voidtobig(char*p){while(*p!='\0'){if((*p)>='a'&&(*p)<='z'){*p=*p-('a'-'A');}p++;//继续循环}}voidtosmall(char*p){while(*p!='\0'){if((*p)>='A'&&(*p)<='Z'){*p=*p+('a'-'A');}p++;//继续循环}}voidmain(){charstr[50]="TASKLIST";charstr2[30]="calc";//scanf("");tobig(str2);printf("%s\n",str2);tosmall(str);printf("%s\n",str);system("pause");return;}