Text Area maxlength not working

Question

I want to set maximum length to the textarea. I am using following code for the same,but it is not working,

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                <span>2021-01-18 02:28</span>
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<p>I tried maxlength in textarea, but does not count the characters correctly(also counts the EOLs).
I use <code>max_length</code> attribute instead of normal <code>maxlength</code>.</p>

<p>HTML:</p>

<pre><code><textarea name="whatever" max_length="100">

JS:

$('textarea').keyup(function(){
  var maxlength = parseInt($(this).attr('max_length')),
      text = $(this).val(),
      eol = text.match(/(\r\n|\n|\r)/g),
      count_eol = $.isArray(eol) ? eol.length : 0,//error if eol is null
      count_chars = text.length - count_eol;
  if (maxlength && count_chars > maxlength)
    $(this).val(text.substring(0, maxlength + count_eol));
});