老人家的舊書房

import java.io.*;

public class ex5_4{
public static void main(String[] alio)
throws IOException{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("請輸入第一個數字：");
String str = br.readLine();
int i = Integer.parseInt(str);
System.out.println("請輸入第二個數字：");
String str2 = br.readLine();
int j = Integer.parseInt(str2);
System.out.println("請輸入想做的計算：");
System.out.println("1.加法，2.減法，3.乘法，4.除法（只列出商數）。");
System.out.print("→");
String str3 = br.readLine();
int k = Integer.parseInt(str3);

switch(k){
case 1:
if(i>j){
System.out.println(i+">"+j);
System.out.println(i+j);
}
else if(i System.out.println(i+" System.out.println(i+j);
}
else{
System.out.println(i+"="+j);
System.out.println(i+j);
}
break;
case 2:
if(i>j){
System.out.println(i+">"+j);
System.out.println(i-j);
}
else if(i System.out.println(i+" System.out.println(i-j);
}
else{
System.out.println(i+"="+j);
System.out.println(i-j);
}
break;
case 3:
if(i>j){
System.out.println(i+">"+j);
System.out.println(i*j);
}
else if(i System.out.println(i+" System.out.println(i*j);
}
else{
System.out.println(i+"="+j);
System.out.println(i*j);
}
break;
case 4:
if(i>j){
System.out.println(i+">"+j);
System.out.println(i/j);
}
else if(i System.out.println(i+" System.out.println(i/j);
}
else{
System.out.println(i+"="+j);
System.out.println(i/j);
}
break;
}
}
}