This article will help you create your own javascript/jQuery word count function. The code below can be used to limit the number of words in a text box(e.g Abstract guideline tool) using the simple javascript with a little bit mix of jQuery.

function WordCount() {
       
        var inp = document.getElementById('txtabstract').value;
     
        var regex = /\s+/gi;
        var wordcount = jQuery.trim(inp).replace(regex, ' ').split(' ').length;      
     
        
        $("#labelcount").html(wordcount);
    }

Here is the working example which can help you count the number of words in a textbox using the code below

Text here : <input type="text" id="txtabstract" value="Testing Word Count" />
Count : <label id="labelcount"></label>

jQuery

function WordCount() {
       //Get Text data
        var inp = document.getElementById('txtabstract').value;
     
        var regex = /\s+/gi;

        var wordcount = jQuery.trim(inp).replace(regex, ' ').split(' ').length;      
            
        
        $("#labelcount").html(wordcount);
    }

  $(document).ready(function(){
    //count word on page load
    WordCount();

    //count word on entering text in TextBox
    $("#txtabstract").on('input',function(){
        WordCount();
 
 
    })  
  })

https://jsfiddle.net/Lrhbv6zv/

Similar code is used to check the total number of words when a user is submitting a project material at Classgist