WooCommerce - Change Checkout Field Label and Place Holder Text

functions.php

<?php
/*
* WooCommerce - Change Checkout Field Label and Place Holder Text -- By Darshan Gada
* For more options: https://docs.woocommerce.com/document/tutorial-customising-checkout-fields-using-actions-and-filters/
*/

// WooCommerce Checkout Fields Hook
add_filter( 'woocommerce_checkout_fields' , 'webgeeks_wc_checkout_fields' );

// This example changes the default placeholder text for the state drop downs to "Select A State"
function webgeeks_wc_checkout_fields( $fields ) {
    $fields['billing']['billing_state']['label'] = 'State';
    $fields['shipping']['shipping_state']['label'] = 'State';
    return $fields;
}
?>