Show stock status next to each attribute value in WooCommerce variable products

Faster and optimized code version for WooCommerce 3+ only in:
Display variation stock status on single dropdown variable products in Wocommerce 3

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Updated WooCommerce compatibility or previous version 2.6.x

You can do it using a custom function hooked in woocommerce_variation_option_name filter hook. This is only viable for products that have a unique attribute for their variations…

Here is the code:

add_filter( 'woocommerce_variation_option_name', 'customizing_variations_terms_name', 10, 1 );
function customizing_variations_terms_name( $term_name ){

    if(is_admin())
        return $term_name;

    global $product;
    $second_loop_stoped = false;

    // Get available product variations
    $product_variations = $product->get_available_variations();

    // Iterating through each available product variation
    foreach($product_variations as $variation){

        $variation_id = $variation['variation_id'];
        $variation_obj = new WC_Product_Variation( $variation_id );

        ## WOOCOMMERCE RETRO COMPATIBILITY ##
        if ( version_compare( WC_VERSION, '3.0', '<' ) ) # BEFORE Version 3 (older)
        {
            $stock_status = $variation_obj->stock_status;
            $stock_qty = intval($variation_obj->stock);

            // The attributes WC slug key and slug value for this variation
            $attributes_arr = $variation_obj->get_variation_attributes();
        }
        else # For newest verions: 3.0+ (and Up)
        {
            $stock_status = $variation_obj->get_stock_status();
            $stock_qty = $variation_obj->get_stock_quantity();

            // The attributes taxonomy key and slug value for this variation
            $attributes_arr = $variation_obj->get_attributes();
        }

        if(count($attributes_arr) != 1) // Works only for 1 attribute set in the product
            return $term_name;

        // Get the terms for this attribute
        foreach( $attributes_arr as $attr_key => $term_slug){
            // Get the attribute taxonomy
            $term_key = str_replace('attribute_', '', $attr_key );

            // get the corresponding term object
            $term_obj = get_term_by( 'slug', $term_slug, $term_key );
            if( $term_obj->name == $term_name ){ // If the term name matches we stop the loops
                $second_loop_stoped = true;
                break;
            }
        }
        if($second_loop_stoped)
            break;
    }
    if( $stock_qty>0 )
        return $term_name .= ' - ' . $stock_status . ' ('.$stock_qty.')';
    else
        return $term_name .= ' - ' . $stock_status;

}

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

This code works and is tested in WooCommerce 2.6.x and 3+.

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You will get this (for example):

You can use other WC_Product_Variation or WC_Product methods to get and display the data you want…