title: Common elements in multiple arrays in angular 6
body: <p>I have multiple arrays of string, what I'm trying to do is extract the common values in a new array.</p>
  
  <p>Let's say we have : </p>
  
  <pre><code>const arr1:string[] = ['0','1','2','3','4'];
  const arr2:string[] = ['0','1','2'];
  const arr3:string[] = ['0','2', '5'];
  const arr4:string[] = ['1','2', '3'];
  </code></pre>
  
  <p>The result should be : </p>
  
  <pre><code>const result:string[] = ['2'];
  </code></pre>
  
  <p>Because <code>2</code> is present in each array.</p>
  
  <p>With two arrays I can use <code>filter</code> but with more than two how can I achieve that ?</p>