Question

For example i declare some variable like test in server side of my PHP

echo('var test = ' . json_encode($abc));

Now i want to use this test variable in Jquery ..how can i use it?

What function do i need to use it?

For Example i have:

I have back end PHP code something like this

$abc = no
echo "var test= ".json_encode($abc);

I want jquery to do the following action(client side)

$(document).ready(function(){
function(json) { 
if($abc == no )//this i what i want to be achieved

  }
}

Answer 1

I think, you dont understand the diference between frontend (JavaScript) and backend (PHP). You can not directly access php variables from javascript. You need to make Ajax-request to some php file, that will return some data that you need in format that you specify.
for example:

<?php
    $result = array('abc' => 'no');
    echo json_encode($result); 
?>

This is serverside script called data.php. In Javascript you can make so:

$(document).ready(function(){
    $.getJSON('data.php', function (data) {
        if(data.abc === 'no') {
            your code...
        }
     });
}