Scanner Class

Source: Dev.to

Class in Java

Definition of the class concept in Java.

Why Scanner?

The Scanner class simplifies reading input from various sources, such as the keyboard.

How to Use Scanner

Step 1: Import the package

import java.util.Scanner;

Step 2: Create a Scanner object

Scanner sc = new Scanner(System.in);

System.in → Takes input from the keyboard.

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();

the subsequent nextLine() may be skipped because nextInt() does not consume the newline character.

Correct way

int age = sc.nextInt();
sc.nextLine(); // consume the remaining newline
String name = sc.nextLine();

Common Scanner Methods

• nextInt() – reads an integer
• nextLine() – reads a line of text
• nextDouble() – reads a double

Always Close Scanner

sc.close();

Example

import java.util.Scanner;

public class Main {
    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(); // consume newline

        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
    }
}