How to take input from user in Java using Scanner

One of the strengths of Java is the huge libraries of code available to you. This is code that has been written to do specific jobs. All you need to do is to reference which library you want to use, and then call a method into action.

One really useful class that handles input from a user is called the Scanner class. The Scanner class can be found in the java.util library. To use the Scanner class, you need to reference it in your code. This is done with the keyword import.

import java.util.Scanner;

We first create an object of Scanner class and then we use the methods of Scanner class. Consider the statement

Scanner a = new Scanner(System.in);

Here Scanner is the class name, a is the name of object, new keyword is used to allocate the memory and System.in is the input stream.

Following methods of Scanner class are used in the program below :-

1.      nextInt() to input an integer

2.      nextFloat() to input a float

3.       nextLine() to input a string

Example:

import java.util.Scanner;

class GetInputFromUser

{

   public static void main(String args[])

   {

                        int i;

                        float f;

                        String s;

             

                        Scanner in = new Scanner(System.in);

             

                        System.out.print("Enter a string: ");

                        s = in.nextLine();

             

                        System.out.print("Enter an integer: ");

                        i = in.nextInt();

                        System.out.print("Enter a float: ");

                        f = in.nextFloat();

                        System.out.println("You entered string: "+s);

                        System.out.println("You entered integer: "+i);

                        System.out.println("You entered float: "+f);

   }

}

Output: