How go give $value to wp_query

Question

Probly easy question but just cant seem to find whats wrong. I cant build a query based on a search when i use ' ' but not when i use a alrdy declared variable.

This works

$query2 = new WP_Query( 's='motorkap met' );
 while( $query2->have_posts() ) {
            $query2->the_post();
echo the_title();?> </br> <?php
}

This doesnt for some reason.... I cant seem to find how to pass the already declared variable

$zoekterm = removeCommonWords('motorkap met'); 

$query2 = new WP_Query( 's=$zoekterm' );
 while( $query2->have_posts() ) {
            $query2->the_post();
echo the_title();?> </br> 
}

Very stupid I know but been searching for over 2 hours alrdy :( must be passing it wrong somehow tried everything from echo, to just $zoekterm to 's='$zoekterm' ' etc...

Answer 1

Assuming removeCommonWords() returns a string, you can do the following:

$zoekterm = removeCommonWords('motorkap met'); 

$query2 = new WP_Query( 
    array(
        's' => $zoekterm
    ) 
);

while( $query2->have_posts() ) {
    $query2->the_post();
    echo the_title() . '</br> ';
}

Sometimes the array notating is more useful than the string notation ...