WordPress - Convert array to string

functions.php

<?php
/**
 * converts array to string.
 *
 * @param $arr
 * @param array $args
 *
 * @return string
 */
function convert_array_to_string( $arr, $args = array() ) {
	$args = wp_parse_args( $args, array(
		'glue'          => ', ',
		'item_template' => '{value}' //  {key} and {value} allowed
	) );
	$transformed_arr = array_map( function ( $key, $value ) use ( $args ) {
		$item = str_replace( array( '{key}', '{value}' ), array( $key, $value ), $args['item_template'] );
		return $item;
	}, array_keys( $arr ), $arr );
	return implode( $args['glue'], $transformed_arr );
}