how to open function in js in php code example

Example 1: php execute javascript

<?php
 if(your condition){
     echo "<script> window.onload = function() {
     yourJavascriptFunction(param1, param2);
 }; </script>";
?>

Example 2: how to call js function from php

<?php
 if(your condition){
     echo "<script> window.onload = function() {
     yourJavascriptFunction(param1, param2);
 }; </script>";
?>