title: javascript - check if string is in a array without case sensitive
body: <p>I want to make a filter. Where if you input a word that is in the 'blacklist' it will tell something. I've got all the code but have a problem.</p>
  
  <p><strong>JS:</strong></p>
  
  <pre><code>input = document.getElementById("input").value;
  array = ["1","2","3"];
  function filter() {
    if (input == array)
    // I will do something.
    } else {
    // Something too
    }
  }
  </code></pre>
  
  <p>I want to make it so that if the <code>input</code> is a item in the <code>array</code>. That the statement is true. But what is the correct way to do this? Because what I'm doing here doesn't work! <strong>Also I want to get rid of the case sensitive!</strong> So that if the array has <code>hello</code> in it both <code>hello</code> and <code>Hello</code> are detected.</p>
  
  <p>Sorry if this question is asked before. I searched for it but didn't know what keywords to use.</p>
  
  <hr/>
  
  <p><strong>EDIT 1:</strong></p>
  
  <p>I am changing my question a little bit:
  I want to check what is in my original question but with some other features.</p>
  
  <p>I also want to check if <code>input</code> has a part of an item in <code>array</code>. So that if the input is <code>hello</code> that <code>helloworld</code> is being detected because is has <code>hello</code> in it. As well as <code>hello</code> or <code>Hello</code>.</p>