add javascript to wordpress functions php

Add the following code to your theme's functions.php file:

function add_custom_js() {
    wp_enqueue_script( 'custom-js', get_template_directory_uri() . '/js/custom.js', array('jquery'), '1.0', true );
add_action('wp_enqueue_scripts', 'add_custom_js');

Explanation: - The add_custom_js function is created to enqueue the custom JavaScript file. - wp_enqueue_script is used to enqueue the script, and it takes several parameters: the handle ('custom-js'), the path to the file using get_template_directory_uri() . '/js/custom.js', any dependencies (in this case, 'jquery'), version number ('1.0'), and whether to load the script in the footer ('true'). - The add_action function is then used to add this custom script to the theme's script queue on the wp_enqueue_scripts hook.