In this post, we will see how to take Input from user in java.

There are times when you want to take input from user and run program according to user input.

There are many ways to take input from user and some of them are:

• Using Scanner
• Using BufferReader

Using  Scanner class

Scanner class is a way to take input from users. Scanner class is available in java.util package so import this package when use scanner class.

Firstly we create the object of  Scanner class. When we create object of Scanner class we need to pass System.in as a parameter which represents standard input stream and that is a predefined object. If we want to take input from a file then we have to pass object of class File.

How  to  create  object  of  scanner class :

Scanner  s=new  Scanner(System.in);

Here  Scanner is a class, s is an object ,new is used to allocate memory and System.in is for the standard input stream.
There are various methods available in Scanner class. Few of them are:

We can use any method according to the type of value we want to read.
Below Source code shows the use of scanner class.

package org.arpit.java2blog;
import java.util.Scanner; //import util hpackage for Scanner class

public class Employee
{
	public static void main(String args[])
	{
		int id;
		String name;
		float salary;
		Scanner s=new Scanner(System.in);
		
		System.out.println("Enter Employee  name:");
		name = s.nextLine(); //taking string input
		
		System.out.println("Enter Employee Id:");
		id = s.nextInt(); //taking integer input

		System.out.println("Enter Employee Salary:");
		salary = s.nextFloat(); //taking float input

		// Printing employee Details
		System.out.println("Employee  details:");
		System.out.println("Employee  name is: " +name);
		System.out.println("Employee  id is: " +id);
		System.out.println("Employee  salary is: " +salary);
		s.close();
	}
}

When you run above program, you will get below output.
Output:

Using  BufferedReader classs

By using  System.in in an InputStreamReader which is wrapped in BufferedReader, we can read input from the user in console. BufferedReader is available in java.io package. when we take input using BufferedReader class it takes all the values as  String so, whenever any other type of values like int, float values are required. We need to parse the value which is in string form using wrapper class for ex: Integer.parseInt  for int, Float.parseFloat  for float values.

Example:

package org.arpit.java2blog;

import java.io.*; //import io package for BufferedReader class

public class BufferedReaderMain
{
	public static void main(String args[])
	{
		try //exception handling is done  here using try and catch block because sometimes  exception occur when uses io classes
		{
			// creation of BufferedReader object
			BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

			System.out.print("Enter Student name:");
			String name=br.readLine(); // to read from console

			System.out.println("Enter Student number:");
			int num=Integer.parseInt(br.readLine()); //parsing of string into into integer type using wrapper class
                        // Printing employee Details
		        System.out.println("Student  details:");
			System.out.println("Student name is:" +name);
			System.out.println("Student number is:" +num);
		}
		catch(IOException e)
		{
			System.out.println(e.getMessage());
		}
	}
}

When you run above program, you will get below output.
Output:

Please note that BufferedReader class is thread safe while  Scanner class is not.

That’s about taking input from user in java.

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