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content/blog/2017-08-28-obtaining-command-line-input-java.md

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+---
+id: 2241
+title: Obtaining Command Line Input in Java
+date: 2017-08-28T17:37:59+00:00
+author: Brandon Rozek
+layout: post
+guid: https://brandonrozek.com/?p=2241
+permalink: /2017/08/obtaining-command-line-input-java/
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+kind:
+  - note
+---
+To obtain console input for your program you can use the <code class="language-java">Scanner</code> class
+
+First import the relevant library
+
+<pre class="language-java"><code class="language-java">
+import java.util.Scanner;
+</code></pre>
+
+Then create a variable to hold the <code class="language-java">Scanner</code> object
+
+<pre class="language-java"><code class="language-java">
+Scanner input;
+input = new Scanner(System.in);
+</code></pre>
+
+Inside the parenthesis, the <code class="language-java">Scanner</code> binds to the System input which is by default the console
+
+The new varible <code class="language-java">input</code> now has the ability to obtain input from the console. To do so, use any of the following methods
+
+<table class="tg">
+  <tr>
+    <th class="tg-yw4l">
+      Method
+    </th>
+    
+    <th class="tg-yw4l">
+      What it Returns
+    </th>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      next()
+    </td>
+    
+    <td class="tg-yw4l">
+      The next space seperated string from the console
+    </td>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      nextInt()
+    </td>
+    
+    <td class="tg-yw4l">
+      An integer if it exists from the console
+    </td>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      nextDouble()             
+    </td>
+    
+    <td class="tg-yw4l">
+      A double if it exists from the console
+    </td>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      nextFloat()
+    </td>
+    
+    <td class="tg-yw4l">
+      A float if it exists from the console
+    </td>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      nextLine()
+    </td>
+    
+    <td class="tg-yw4l">
+      A string up to the next newline character from the console
+    </td>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      hasNext()
+    </td>
+    
+    <td class="tg-yw4l">
+      Returns true if there is another token
+    </td>
+  </tr>
+  
+  <tr>
+    <td class="tg-yw4l">
+      close()
+    </td>
+    
+    <td class="tg-yw4l">
+      Unbinds the Scanner from the console
+    </td>
+  </tr>
+</table>
+
+Here is an example program where we get the user&#8217;s first name
+
+<pre class="language-java"><code class="language-java">
+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); 
+  }
+}
+</code></pre>