trjhtr

Is there a better way to ask for input and give answers, but without so many lines? Each input will give a specific output according to a key that I use, but this many lines seems excessive. I'm a beginner to java and could use some ideas on how to optimize this coding.

 import java.util.Scanner; 
 class Test 
 public static void main (String args) 

 System.out.print ("Enter the day of the month - Answer: "); 
 Scanner inputFigure = new Scanner (System.in); 
 int i = inputFigure.nextInt (); 
 if ( i==1) 
 System.out.println ("12");
 
 else if (i==2) 
 System.out.println ("13");
 
 else if (i==3) 
 System.out.println ("14");
 
 else if (i==4) 
 System.out.println ("11");
 
 else if (i==5) 
 System.out.println ("12");
 
 else if (i==6) 
 System.out.println ("13");
 
 else if (i==7) 
 System.out.println ("14");
 
 else if (i==8) 
 System.out.println ("11");
 
 else if (i==9) 
 System.out.println ("12");
 
 else if (i==10) 
 System.out.println ("21");
 
 else if (i==11) 
 System.out.println ("22");
 
 else if (i==12) 
 System.out.println ("23");
 
 else if (i==13) 
 System.out.println ("24");
 
 else if (i==14) 
 System.out.println ("21");
 
 else if (i==15) 
 System.out.println ("22");
 
 else if (i==16) 
 System.out.println ("23");
 
 else if (i==17) 
 System.out.println ("24");
 
 else if (i==18) 
 System.out.println ("21");
 
 else if (i==19) 
 System.out.println ("22");
 
 else if (i==20) 
 System.out.println ("31");
 
 else if (i==21) 
 System.out.println ("32");
 
 else if (i==22) 
 System.out.println ("33");
 
 else if (i==23) 
 System.out.println ("34");
 
 else if (i==24) 
 System.out.println ("31");
 
 else if (i==25) 
 System.out.println ("32");
 
 else if (i==26) 
 System.out.println ("33");
 
 else if (i==27) 
 System.out.println ("34");
 
 else if (i==28) 
 System.out.println ("31");
 
 else if (i==29) 
 System.out.println ("32");
 
 else if (i==30) 
 System.out.println ("41");
 
 else if (i==31) 
 System.out.println ("42");
 
 else 
 System.out.println ("Invalid entry for the day. Try again.");
 

The best way to shorten the code would be to write a formula for it. That formula should be packaged into a function:

public static String outputForDay(int day) 
 if (!(1 <= day && day <= 31)) 
 throw new IllegalArgumentException("Invalid entry for the day.");
 
 int onesDigit = day % 10,
 tensDigit = day / 10;
 return Integer.toString(10 * (tensDigit + 1) + (onesDigit % 4) + 1);

Then, you would call the function like this:

public static void main(String args) 
 try (Scanner scanner = new Scanner(System.in)) 
 System.out.print("Enter the day of the month: ");
 System.out.println(outputForDay(scanner.nextInt()));
 catch (IllegalArgumentException e) 
 System.out.println(e.getMessage());
 

You can use what is called a Map.
So basically you will create your map with

Map<KEY, VALUE> map = new HashMap<KEY, VAlUE>();

Your case would be something like this:

map<Integer, String> map = new HashMap<Integer, String>();

Then put the values as so:

map.put("World/Value", "What is would equal");

in your case, it would be

map.put(1, "12").put(2,"13").build();

To do what you are trying to do you can create a for loop and

System.out.println(map.get(VALUE));

For example,

System.out.println(map.get(1));

and this would return "12"