시소당

대문자, 소문자 변환

대문자  A  -  Z는  65  -  90의  아스키코드값을  가지고  있고,
소문자  a  -  z  는  97  -  122의  아스키코드값을  가지고  있습니다.  

입력  받은  문자열의  하나의  문자를  가져와  대문자와  소문자  사이의  값  32를  이용합니다.  

문자가  a  -  z인  97  -  122  사이에  속한  문자라면  32를  빼  대문자로  변환하고,
A  -  Z인  65  -  90사이에  속한  문자라면  32를  더해  소문자로  변환하시면  됩니다.  

import  java.io.*;

class  StringConversion
{
                public  static  void  main(String[]  args)  throws  IOException

                {
                                //  입력  스트림을  생성
                                BufferedReader  br  =  new  BufferedReader(new  InputStreamReader(System.in));

                                //  유저에게  문자열을  입력  받아  char형의  배열로  변환
                                System.out.println("변환할  문자열을  입력  하세요.");

                                char[]  str  =  br.readLine().toCharArray();
  
                                //  문자열의  갯수  만큼  루프를  돔.
                                for(int  i=0;  i<str.length;  i++)
                                {

                                                //  각  인덱스의  문자가  소문자라면  대문자로  변환
                                                if((str[i]  >=  97)  &&  (str[i]  <=  122))
                                                {
                                                                str[i]  -=  32;
                                                }
                                                //  각  인덱스의  문자가  대문자라면  소문자로  변환
                                                else  if((str[i]  >=  65)  &&  (str[i]  <=  90))
                                                {
                                                                str[i]  +=  32;
                                                }
                                }
                                //  결과  출력
                                System.out.println(str);
                }
}