how come i keep getting java.lang.NullPointerException whenever i use console.readLine in applications like eclipse?

Maybe check your imports? make sure you have import java.io.Console;

if you are trying to get input from the console you could also use the scanner class. it would look something like: make sure you import java.util.Scanner;

Scanner sc = new Scanner(System.in);
System.out.print("Name: ");
String name = sc.nextLine();

The problem is that the Console class does not work in most Java IDEs due to the way they run your program. This stackoverflow post provides a more detailed explanation as to why it does not work if you are curious. If you compiled your program in Eclipse and ran it in a console manually then it would work fine.

This means that you have to use alternative ways to print and get input when working in your IDE.

To print you can use System.out instead of console like this:

System.out.println("Text you want to be printed to console");

System.out also has a printf and print method just like the Console class, that works in the same way as the Console equivalents

And to get input you can use the Scanner class like this:

import java.util.Scanner; // Place this at the top of your code to import the Scanner

Scanner scanner = new Scanner(System.in); // Write this in your method once
String input = scanner.nextLine(); // Then use scanner.nextLine as a substitute for console.readLine