C Programming (Fifth Edition) Example 4.4
The following is a different method from the textbook
Enter a character and determine whether it is an uppercase letter, if it is, convert it to a lowercase letter; if it is not, do not convert it. Then output the final character.
#include<stdio.h>
int main()//C语言需要的格式
//由题意可判断此题需要条件表达式处理
{
char ch;//因为输入为字符，用char定义
scanf("%c",&ch);//因为输入为字符，使用%c;不要缺少符号&
if(ch>='A'&&ch<='Z')
/*此处判断输入字符的大小写
符号&&的意思是且，即两边条件都要满足*/
ch=ch+32;//如果为大写字母，则ch加上32，再赋值给ch
printf("%c",ch);
return 0;
}