WorkOut.java

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class WorkOut {

    private static final int range = 6;

    public static void main(String[] args) {

        Scanner kb = new Scanner(System.in);
        System.out.println("Pick a workout day (Chest Day, Leg Day, Back Day):");
        String workOut = kb.nextLine();

        System.out.printf("You entered %s.\n",workOut);
        System.out.println("Here are the workouts: ");

        if (workOut.equalsIgnoreCase("Chest Day")) {
            // System.out.println(Arrays.toString(chestDay()));
            printArray(chestDay());
        } else if (workOut.equalsIgnoreCase("Leg Day")) {
            printArray(legDay());
        } else if (workOut.equalsIgnoreCase("Back Day")) {
            printArray(backDay());
        } else {
            System.out.println("Invalid choice made. Choose between Chest, Leg or Back days only.");
        }
    }

    public static String[] backDay() {
        List<String> backList = new ArrayList <>();
        backList.add("Deadlift");
        backList.add("Pull Up");
        backList.add("Back Rows");
        backList.add("Bend-Over Barbell Rows");
        backList.add("Romanian Deadlift");
        backList.add("Front Squat");

        return randomizerHelper(backList);
    }

    public static String[] chestDay() {
        List <String> chestList = new ArrayList <>();
        chestList.add("Bench Press");
        chestList.add("Incline Press");
        chestList.add("Dip");
        chestList.add("Flys");
        chestList.add("Reverse Flys");
        chestList.add("Supine Press");

        return randomizerHelper(chestList);
    }

    public static String[] legDay() {
        List<String> legList = new ArrayList <>();
        legList.add("Squat");
        legList.add("Leg Press");
        legList.add("Leg Extension");
        legList.add("Dumbbell Step Up");
        legList.add("Body Weight Calf Raises");
        legList.add("Walking Lunge");

        return randomizerHelper(legList);
    }

    private static String[] randomizerHelper(List<String> arr) {
        String[] returnArray = new String[3];
        String chosen;
        for(int i = 0; i < returnArray.length; i++) {
            chosen = arr.get((int) (Math.random() * range));

            for(int j = 0; j < returnArray.length; j++) {
                if (!(chosen.equalsIgnoreCase(returnArray[j]))) {
                    returnArray[i]= chosen;
                    break; // AVOIDS DUPLICATES!
                }
            }
        }
        return returnArray;
    }

    // Helper method to print array
    // Or if you do not want to use this, use:
    // System.out.println(Arrays.toString(chestDay(range))); in the main method
    private static void printArray(String[] arr) {
        for (String val : arr) {
            System.out.println(val);
        }
    }
}