- str_replace: documentation ( source)
- compact: documentation ( source)
<?php
$str = "We have received ##AMOUNT## ##CURRENCY## for your OrderID n. ##ORDER_ID##";
$AMOUNT = 123;
$CURRENCY = 'GBP';
$ORDER_ID = 20123;
$find = ['##AMOUNT##','##CURRENCY##','##ORDER_ID##'];
$replace = compact('AMOUNT', 'CURRENCY', 'ORDER_ID');
echo str_replace($find, $replace, $str);