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 (Very Important 🔥)

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
Java
Copy code
sc.close();