Brandon Rozek

Thoughts on Web Development, Statistics, and Linux

Obtaining Command Line Input in Java

To obtain console input for your program you can use the Scanner class

First import the relevant library


import java.util.Scanner;

Then create a variable to hold the Scanner object


Scanner input;
input = new Scanner(System.in);

Inside the parenthesis, the Scanner binds to the System input which is by default the console

The new varible input now has the ability to obtain input from the console. To do so, use any of the following methods

Method What it Returns
next() The next space seperated string from the console
nextInt() An integer if it exists from the console
nextDouble()              A double if it exists from the console
nextFloat() A float if it exists from the console
nextLine() A string up to the next newline character from the console
hasNext() Returns true if there is another token
close() Unbinds the Scanner from the console

Here is an example program where we get the user’s first name


import java.util.Scanner;

public class GetName {
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.print("Please enter your name: ");
    String firstName = input.next();
    System.out.println("Your first name is " + firstName); 
  }
}