title: How to get longest substring from array of strings using javascript
body: <p>I have array:</p>
  
  <pre><code>let arr = ["logerror", "log:today", "log:1"]
  </code></pre>
  
  <p>I am looking for function how to get longest substring from this items.</p>
  
  <p>Result:</p>
  
  <pre><code>log
  </code></pre>
  
  <p>Another example:</p>
  
  <pre><code>   let arr = ["dog+ěě+", "dog15qwqqq", "dogggggg"]
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>dog
  </code></pre>
  
  <p>Sure, I can write some algorithm, but is there any simple way?</p>
  
  <p>How? Thanks</p>