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
}
}
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