Error typing IF and Else in jquery

Question

I’m starting to venture now into the world of development and hit a question while using IF and Else.

The code below is OK

    <select id="course_list" >
      <?php $my_query = new WP_Query('tribe_events_cat=petroleo-e-gas'); ?>
         <?php while ($my_query->have_posts()) : $my_query->the_post(); ?>
            <option value="course_<?php the_ID(); ?>" >
                <?php the_title(); ?>
            </option>
        <?php endwhile; ?>
    </select>

<script type="text/javascript">
$("#course_list").on('change', function(){
        $('.course_item').hide();
        $('#' + this.value).show();

    });
</script>

But when I try to improve the code and to re-show all the courses, everything stopped working.

<select id="course_list" >
        <?php $my_query = new WP_Query('tribe_events_cat=petroleo-e-gas'); ?>
        <?php while ($my_query->have_posts()) : $my_query->the_post(); ?>
        <option value="all-posts" >
            Mostrar Todos
        </option>
        <option value="course_<?php the_ID(); ?>" >
            <?php the_title(); ?>
        </option>
        <?php endwhile; ?>
    </select>
    <script type="text/javascript">
    $("#course_list").on('change', function(){

        if {
            $('.course_item').hide();
            $('#' + this.value).show();
           }

        else

            $('.course_item=').show();


        });
    </script>

Answer 1

Hello!

Your code has a syntax error in the "if Else" block. To correct you will need to put a condition to be tested inside if. For example:

if(ALGUMA_VARIAVEL == CONDICAO) {
    $('.course_item').hide();
    $('#' + this.value).show();
} else
    $('.course_item=').show();

If the condition is met at some point, your 'if' block will be executed, otherwise the 'Else' will always be executed'.