Hide all/some shipping options when free shipping is available

gistfile1.php

/**
 * woocommerce_package_rates is a 2.1+ hook
 */
add_filter( 'woocommerce_package_rates', 'hide_shipping_when_free_is_available', 10, 2 );
 
/**
 * Hide shipping rates when free shipping is available
 *
 * @param array $rates Array of rates found for the package
 * @param array $package The package array/object being shipped
 * @return array of modified rates
 */
function hide_shipping_when_free_is_available( $rates, $package ) {
 	
 	// Only modify rates if free_shipping is present
  	if ( isset( $rates['free_shipping'] ) ) {
  	
  		// To unset a single rate/method, do the following. This example unsets flat_rate shipping
  		unset( $rates['flat_rate'] );
  		
  		// To unset all methods except for free_shipping, do the following
  		$free_shipping          = $rates['free_shipping'];
  		$rates                  = array();
  		$rates['free_shipping'] = $free_shipping;
	}
	
	return $rates;
}

Hello Renegadesk,
Please help me!
I would like to hide the other shipping options, when the free shipping option is available.
Please write to me excatly, where and what code have to paste?
Thanks in advance,

Are you sure guys that this snippet will work again? I added to my function.php, but I have local_pickup, free_shipping and flat_rate that should be unset but it's not. I created a flat_rate just to make sure to have one, but I want to hide it. 99,99% of sells on my ecommerce have free_shipping, 0,01% have local_pickup. Flat_rate shouldn't be there, it's annoying for my customers. How can I fix it?

The example does not seem to work!

The example does not seem to work! Okay I had a caching problem with WooCommerce Transients

Works great! THANKS!

Worked great until the update to 2.6.
Did they changed the hooks with the new "shipping zones"-feature?

I'm just here to thank you. Graet job, thanks a lot.