Using Form to alter PHP variable [closed]

Question

I'm pulling custom posts by their meta_key using this function:

<?php $args = array(
    'numberposts'     => 10,
    'meta_key'        => 'allvotes',
    'orderby'         => 'meta_value',
    'order'           => 'DESC',
    'post_type'       => 'things',
    'post_status'     => 'publish' );
$mystuff = get_posts( $args );
?> 

I want to involve a form which will edit my variables, but when I try my code, it doesn't return any posts...

<?php
 $filter = $_POST['country'];
 $submit = $_POST['submit'];
 if(isset($submit)){
    $args = array(
    'numberposts'     => 10,
    'meta_key'        => '$filter',
    'orderby'         => 'meta_value',
    'order'           => 'DESC',
    'post_type'       => 'things',
    'post_status'     => 'publish' );
$mystuff = get_posts( $args );
$name = $filter ;
}
else {
    $args = array(
    'numberposts'     => 10,
    'meta_key'        => 'canada',
    'orderby'         => 'meta_value',
    'order'           => 'DESC',
    'post_type'       => 'things',
    'post_status'     => 'publish' );
$mystuff = get_posts( $args );
$name = 'Everywhere';
};
?>

Answer 1

Don't put your variables in single quotes.

This:

if(isset($submit)){
    $args = array(
        'numberposts'     => 10,
        'meta_key'        => '$filter',
        'orderby'         => 'meta_value',
        'order'           => 'DESC',
        'post_type'       => 'things',
        'post_status'     => 'publish' );
    $mystuff = get_posts( $args );
    $name = $filter ;
}

Should be this:

if(isset($submit)){
    $args = array(
        'numberposts'     => 10,
        'meta_key'        => $filter,
        'orderby'         => 'meta_value',
        'order'           => 'DESC',
        'post_type'       => 'things',
        'post_status'     => 'publish' );
    $mystuff = get_posts( $args );
    $name = $filter ;
}