#include <stdio.h>
int main()
{
char ch=0;
while(~scanf(" %c",&ch))
{
if(isupper(ch))
printf("%c\n",tolower(ch));
else if(islower(ch))
printf("%c\n",toupper(ch));
}
return 0;
} #include <stdio.h>
int main()
{
char ch;
while(scanf("%c\n",&ch)!=EOF)
{
{
if(ch>='a'&&ch<='z')
{ch=toupper(ch);
printf("%c\n",ch);}
else if(ch>='A'&&ch<='Z')
{ch=tolower(ch);
printf("%c\n",ch);}
}
}
return 0;
}
//养成好习惯,if语句后面要有括号,超过一行不打括号会报错; #include<stdio.h>
int main()
{
int ch;
while((ch=getchar())!=EOF){
getchar();
if(ch>=65 && ch<=90){
ch+=32;
putchar(ch);
}
else if(ch>=97 && ch<=122){
ch-=32;
putchar(ch);
}
else
continue;
printf("\n");
}
return 0;
}