Question

_{PLEASE USE ARRAYS IN JAVA TO ANSWER THIS}

Write a 'main' method that examines its command-line arguments and

• calls the (add) method if the first parameter is a "+"
• calls the (subtract) method if the first parameter is a "-"
• calls the (doubled) method if the first parameter is a "&"

add should add the 2 numbers and print out the result.
subtract should subtract the 2 numbers and print out the results.
Double should add the number to itself and then output the result.

Command line arguments + 5 2 : should print 7
Command line arguments - 5 2 : should print 3
Command line arguments & 5 : should print 10

Answer 1

JAVA CODE:

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class MyClass
{
public static int add(int x, int y){
return x+y;
}
public static int subtract(int x, int y){
return x+y;
}
public static int doubled(int x){
return x+x;
}
   public static void main (String[] args)
   {
   char sign = args[0].charAt(0);
       if(sign=='+'){
       int first =Integer.parseInt(args[1]);
       int second = Integer.parseInt(args[2]);
       System.out.println(add(first,second));
       }
       else if(sign=='-'){
       int first =Integer.parseInt(args[1]);
       int second = Integer.parseInt(args[2]);
       System.out.println(subtract(first,second));
       }
       if(sign=='&'){
       int first =Integer.parseInt(args[1]);
       System.out.println(doubled(first));
       }
   }
}

OUTPUT:

CommandLine arguments

+12

result:

3