Scanner Class

Class in Java

Definition

The Scanner class is a predefined class in Java used to take input from the user.

It belongs to:

java.util package

Why Scanner?

It is used to read:

int

double

float

String

boolean

long

etc.

How to Use Scanner

Step 1: Import the package

import java.util.Scanner;

Step 2: Create Scanner Object

Scanner sc = new Scanner(System.in);

✔ System.in → Takes input from keyboard

✔ sc → Object name

Step 3: Take Input

int age = sc.nextInt();

String name = sc.nextLine();

double salary = sc.nextDouble();

Important Concept:

If you write:

int age = sc.nextInt();

String name = sc.nextLine();

The nextLine() may get skipped because nextInt() does not consume the newline.

Correct way:

int age = sc.nextInt();

sc.nextLine(); // consume leftover newline

String name = sc.nextLine();

Common Scanner Methods

nextInt()-Integer

nextDouble() - Decimal number

next() - Single word

nextLine() - Full sentence

nextBoolean() - true/false

Always Close Scanner

sc.close();

Example:

If we want to get the 5 subject marks from user and print the total we can use the scanner class and achieve this.

import java.util. Scanner;

public class TotalMarks {

    public static void main(String[] args) {



        Scanner sc = new Scanner(System.in);



        System.out.println("Enter Tamil mark:");

        int tamil = sc.nextInt();



        System.out.println("Enter English mark:");

        int english = sc.nextInt();



        System.out.println("Enter Maths mark:");

        int maths = sc.nextInt();



        System.out.println("Enter Science mark:");

        int science = sc.nextInt();



        System.out.println("Enter Social mark:");

        int social = sc.nextInt();

        sc.nextLine();



        System.out.println("Student name");



        String name = sc.nextLine();



        int total = tamil + english + maths + science + social;

        System.out.println("Total Marks" + total);

        System.out.println("Student name"+name);



        sc.close();   // Good practice

    }

}