Please put some more effort on your query, for sure you can come up with your answers by yourself and you will learn faster. For now You can refer to below answer.

package com.barnwal.jeetendra.learn;
import java.util.Scanner;

public class Assignment4 {

    public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    System.out.print("Enter the first integer:");
    int first = s.nextInt();
    System.out.print("Enter the second integer:");
    int second = s.nextInt();
    System.out.println("How many integers are between " + first + " and "
            + second + "???");

    // To print number of integer between entered number
    if (second > first) {
        System.out.println("Answer : " + (second - first - 1));

        // To print the numbers
        for (int i = first + 1; i < second; i++)
            System.out.print(i + " ");
    } else {
        // To print number of integer between entered number
        System.out.println("Answer : " + (first - second - 1));

        // To print the numbers
        for (int i = second + 1; i < first; i++)
            System.out.print(i + " ");
    }
 }
}

In Java 8 you can do it in this way using IntStream

    int lowNum = Integer.parseInt(minInput.getText());
    int highNum = Integer.parseInt(maxInput.getText());

    StringBuilder sb = new StringBuilder();

    IntStream.rangeClosed(lowNum, highNum).forEach(no -> {
        sb.append(no);
    });

    outputLabel.setText(sb.toString());

Use a for loop like so:

    System.out.println("enter a number : ");
    int i = input.nextInt();
    System.out.println("enter another number : ");
    int b = input.nextInt();

    for(int j = i+1; j <= b; j++){
        System.out.println(j);
    }

When you input 1 16 it produces:

6
7
8
9
10
11
12
13
14
15

As you are incrementing value first so you can try this approach

import java.util.Scanner;
public class Practice2 {
public static void main(String[] args) {
int num1;
int num2;
Scanner input= new Scanner(System.in);
System.out.println("Input one integer");
num1= input.nextInt();
System.out.println("Enter another integer");
num2= input.nextInt();
while(num1<num2-1) {
num1 += 1;
System.out.println(num1);
}
while(num2<num1-1){
num2+=1;
System.out.println(num2);
}


}
}

Wrong main() method declaration. You have to pass an array as the only parameter for this function.

Then either declare your start and stop variables as local, and do the job inside the main method itself, or create a new function you call from the main() method.

No more explanation needed, this is Java basics. You should read a Java lesson.

The print method will simply convert its argument to a string and write out the result. Therefore, if you want to display the two numbers concatenated, you will need to do this yourself by converting them to a string (either explicitly, or using "" as you've already mentioned).

If you want to avoid building the string yourself, you'd probably need to use the printf() method:

System.out.printf("%d%d", a, b);

1. FirstNumber and SecondNumber are assigned to 0, but we actually want to get it assigned from Scanner. here are some useful examples. https://www.w3schools.com/java/java_user_input.asp

2. the while loop does nothing because the conditional code is an empty statement. the link might be very helpful. https://www.tutorialspoint.com/java/java_while_loop.htm

   import java.util.Scanner;
   
   public class EveryOther {
   
       public static void main(String[] args) {
   
           int FirstNumber = 0;
           int SecondNumber = 0;
   
           Scanner scanner = new Scanner(System.in);
           System.out.print("FirstNumber: " );
           FirstNumber = scanner.nextInt();
   
           System.out.print("Second Number: ");
           SecondNumber = scanner.nextInt();
   
           while (FirstNumber < SecondNumber){
               System.out.println(FirstNumber);
               FirstNumber = FirstNumber + 2;
           }
       }
   

   }

You cannot decide that a number if prime if it is not divisible by a number. You need to add to the result at the end of the inner loop.

There are quite a few problems in your code. Here's the working one

for(int i= beg; i<= end; i++) {
    boolean prime = true;  //start by assuming the current number is prime
    for(int j=2; j<i; j++) { // Loop till j < i
        if(i%j == 0) {
          prime = false; //Set the current number as not prime if it is divisible by any number lesser than it
        }
   }
   if (prime) {
       res += i+ " ";   //Add to result
   }
}

Note: As sanit@ answer says, you can terminate the loop much earlier. Refer to this to know why looping till square root of the number is enough.