Scanner class in Java — Java Technical Interview Questions & Answers

Scanner class in Java

Scanner class in Java

  • Scanner class in Java: state the definition in one sentence. For Scanner class in Java, know the key keywords / API types involved.
  • Be ready with one tiny runnable Scanner class in Java example.
  • Mention one common Scanner class in Java mistake and the fix.
  • Write one tiny example for Scanner class. Compile, print one result, and say the output out loud before you type.
  • Use Scanner class only when the problem needs it. Don’t force it into every program. Know one beginner trap.
  • Let's take this on the board with one tiny Main class — no extra files. Scanner class in Java — scanner reads ints from a string source and adds them. Start from main, go line by line, and stop at each print. That output is the proof for Scanner class.

Technical Interview Tip: Explain Scanner class in Java as: definition → why → one code idea.

Code Examples for Scanner class in Java

Example

import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner("10 20");
    System.out.println(sc.nextInt() + sc.nextInt()); // 30
    sc.close();
  }
}

Scanner class in Java — scanner reads ints from a string source and adds them.

How to Explain Scanner class in Java to an Interviewer

What is Scanner class?

Scanner class is a Java idea you should explain with one small example. Know the keyword / API used for Scanner class. Type a tiny Main and print one result. For Scanner class, say the output before you code.

Why do we use Scanner class in Java?

Makes the program clearer or safer Scanner class is a Java idea you should explain with one small example.

Write one small example of Scanner class.

Show syntax Say what prints

What mistake do beginners make with Scanner class?

Only the name, no example Scanner class — only memorising the heading. No example, no trap.

Where is Scanner class used in a real program?

Day-to-day Java code