Field editor format output using comma instead of period, and vice versa

functions.php

<?php

add_filter('field_editor_get_custom_field_listing_meta', 'format_job_price_for_germany', 10, 4);

function format_job_price_for_germany($field_value, $field_slug, $listing_id, $args) {
    // Check if the field slug is 'job_price'
    if ($field_slug == 'job_price') {
        // Ensure the field value is not empty and is a numeric value
        if (!empty($field_value) && is_numeric($field_value)) {
            // Format the number to German standards: comma for decimal and period for thousands
            $field_value = number_format((float)$field_value, 2, ',', '.');
            return $field_value;
        }
    }
    // Return the original value if conditions are not met
    return $field_value;
}

functions2.php

<?php
add_filter('field_editor_get_custom_field_listing_meta', 'format_job_price_for_germany', 10, 4);

function format_job_price_for_germany($field_value, $field_slug, $listing_id, $args) {
    // Check if the field slug is 'job_price'
    if ($field_slug == 'job_price') {
        // Ensure the field value is not empty and is a numeric value
        if (!empty($field_value) && is_numeric($field_value)) {
            // Create a number formatter for German locale
            $formatter = new NumberFormatter('de_DE', NumberFormatter::DECIMAL);
            $field_value = $formatter->format($field_value);
            return $field_value;
        }
    }
    // Return the original value if conditions are not met
    return $field_value;
}

The functions2.php version uses NumberFormatter which may or may not be installed on your hosting providers system