// Example 3.1：將大寫字母轉換為小寫字母
#include <iostream.h>
int mylower(int ch)
{
	if(ch>='A' && ch<='Z')
		ch = ch-'A'+'a';
	return ch;
}
void main()
{
	char s[] = "HELLO, C!";
	int  i   = 0, c;
	
	while(s[i]!=0)
	{
		c = s[i];
		s[i]=mylower(c);
		i = i+1;
	}
	cout<<s<<endl;
}