jquery validation of a single element

reference :

https://stackoverflow.com/questions/36407724/jquery-validation-disabling-onkeyup-for-an-element
https://forum.jquery.com/topic/jquery-validate-onkeyup-for-single-field

Passing php array into javascript variable

<?php
// php array
$fruits = array('apple', 'orange', 'mango', 'banana', 'strawberry');
?>

<script type="text/javascript">
// use php implode function to build string for JavaScript array literal
var fruits = <?php echo '["' . implode('", "', $fruits) . '"]' ?>;
// ["apple", "orange", "mango", "banana", "strawberry"]
</script>

source : 

https://www.dyn-web.com/tutorials/php-js/array.php

regex tester

script :

var paragraph = '222323';

var regex = '[0-9]{3,}'; //with at least 3 and above digits

var found = paragraph.match(regex);



console.log(found);

//which return back the array of numbers

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/match

Postcode validation

https://stackoverflow.com/questions/17920096/php-validation-1st-line-of-address-and-postcode

React - Introduction to JSX