was SUPPOSED to be a resize function. Useless, but just saving it.

// in css:
/* Display line under clicked navbar link */
.active {
  text-decoration-line: underline !important;
  text-decoration-thickness: 2px !important;
  color: rgb(20, 19, 19);
}

//in html: 
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>

    <script>
      $(document).ready(function () {
        // Underline to remain in navbar after click using URL
        jQuery(function ($) {
          var path = window.location.href; // because the 'href' property of the DOM element is the absolute path
          $('.nav-link').each(function () {
            if (this.href === path) {
              $(this).addClass('active');
            }
          });
        });
      });
    </script>

//Note class in link should be nav-link

This method gets vowels (‘a’, ‘e’, ‘i’, ‘o’, ‘u’) found in a string.
   
#make a function:
def get_vowels(string):

#return is the keyword which means function have to return value: 
 return [each for each in string if each in 'aeiou']


#assign the words and function will return vowels words.
get_vowels('foobar') # ['o', 'o', 'a']


get_vowels('gym') # []

$.ajax({
  type: "POST",
  url: url,
  data: data,
  success: success,
  dataType: dataType
});

var allElements = $("*");

def when(predicate, when_true):
  return lambda x: when_true(x) if predicate(x) else x
  
EXAMPLES
double_even_numbers = when(lambda x: x % 2 == 0, lambda x : x * 2)
double_even_numbers(2) # 4
double_even_numbers(1) # 1

def unfold(fn, seed):
  def fn_generator(val):
    while True: 
      val = fn(val[1])
      if val == False: break
      yield val[0]
  return [i for i in fn_generator([None, seed])]
  
  
EXAMPLES
f = lambda n: False if n > 50 else [-n, n + 10]
unfold(f, 10) # [-10, -20, -30, -40, -50]

$("#slideshow > div:gt(0)").hide();

setInterval(function() { 
  $('#slideshow > div:first')
    .fadeOut(1000)
    .next()
    .fadeIn(1000)
    .end()
    .appendTo('#slideshow');
},  3000);

$(window).bind("pageshow", function() {
    var form = $('form'); 
    // let the browser natively reset defaults
    form[0].reset();
});

<script>
jQuery( document ).ready(function($){
	$(document).on('click','.elementor-location-popup a', function(event){
		elementorProFrontend.modules.popup.closePopup( {}, event);
	})
});
</script>

// THE HTML/PHP

// Categories Nav START
<? $terms = get_terms( array(
    'taxonomy' => 'category-name', // <-- update this
    'orderby' => 'ID',
  )); 
  if ( $terms && !is_wp_error( $terms ) ){ ?>
   <ul class="CHANGEME-categories-nav">
      <? foreach( $terms as $term ) { ?>
        <li id="cat-<?php echo $term->term_id; ?>">
           <a href="#" class="<?= $term->slug; ?> ajax" data-term-number="<?= $term->term_id; ?>" title="<?= $term->name;?>"><?= $term->name; ?></a>
        </li>
      <? } ?>
   </ul>
<? } ?>
// Categories Nav END
                                       
// Results Container START
<div id="CHANGEME-results-container" class="CHANGEME-filter-result">
   <? // post query
     $query = new WP_Query( array(
        'post_type' => 'post-name', // <-- update this
        'posts_per_page' => -1,
      ) ); 
   if( $query->have_posts() ): while( $query->have_posts()): $query->the_post(); ?>
    
      // POST TEMPLATE HERE
    
   <? endwhile; endif; wp_reset_query(); ?>
</div>                      
// Results Container END

// The onpage JS for the page template
<script>
(function($) {
        'use strict';
        function cat_ajax_get(catID) {
            jQuery.ajax({
                type: 'POST',
                url: raindrop_localize.ajaxurl,
                data: {"action": "filter", cat: catID },
                success: function(response) {
                    jQuery("#CHANGEME-results-container").html(response);
                    return false;
                }
            });
        }
        $( ".CHANGEME-categories-nav a.ajax" ).click(function(e) {
            e.preventDefault();
            $("a.ajax").removeClass("current");
            $(this).addClass("current"); //adds class current to the category menu item being displayed so you can style it with css
            var catnumber = $(this).attr('data-term-number');
            cat_ajax_get(catnumber);
        });

    })(jQuery);
</script>
                                       
// Callback function for functions.php or some other functions specific php file like theme.php
// Aside from the inital add actions and a few other things, the actual query and post template should be the same as what is on the page.
                                       
add_action( 'wp_ajax_nopriv_filter', 'CHANGEME_cat_posts' );
add_action( 'wp_ajax_filter', 'CHANGEME_cat_posts' );
                                       
function CHANGEME_cat_posts () {
    $cat_id = $_POST[ 'cat' ];
    $args = array (
	  'tax_query' => array(
		    array(
		      'taxonomy' => 'category-name', // <-- update this
		      'field' => 'term_id',
		      'terms' => array( $cat_id )
		    )
		  ),
	    'post_type' => 'post-name', // <-- update this
	    'posts_per_page' => -1,
	  );
	global $post;
    $posts = get_posts( $args );
    ob_start ();
    foreach ( $posts as $post ) { 
	    setup_postdata($post); ?>

	    // POST TEMPLATE HERE

   <?php } wp_reset_postdata();
   $response = ob_get_contents();
   ob_end_clean();
   echo $response;
   die(1);
}

<script> 
jQuery(document).ready(function($) { 
var delay = 100; setTimeout(function() { 
jQuery('.elementor-tab-title').removeClass('elementor-active');
jQuery('.elementor-tab-content').css('display', 'none'); }, delay); 
}); 
</script>

from functools import reduce

def compose(*fns):
  return reduce(lambda f, g: lambda *args: f(g(*args)), fns)


EXAMPLES
add5 = lambda x: x + 5
multiply = lambda x, y: x * y
multiply_and_add_5 = compose(add5, multiply)

multiply_and_add_5(5, 2) # 15

#define a function 
 1.Def cube(num)
      #write the formula of cube
      2.return num*num*num
     #give the number to calculate the cube 
     3.cube(3)
   # print the cube of that number simply by using print command
    4.print(cube(3))
     5.“return” keyword means that function have to return value         

#define function
defall_unique(lst):

   return len(lst) == len(set(lst))
   
x = [1,1,2,2,3,2,3,4,5,6]


y = [1,2,3,4,5]


all_unique(x) # False
all_unique(y) # True

 # give a name of function after def
 1.def sayhi():
      #put the statement in the function  
     2.print(“hello world”)
#call function by name:
3.sayhi()


Output: 
Hello world