- var_dump: documentation ( source)
- str_replace: documentation ( source)
<?php
$singleLine = ['line 1 first item', 'line 1 second item'];
var_dump(str_replace('item', 'ITEM', $singleLine));
$lines = [
['line 1 first item', 'line 1 second item'],
['line 2 first item', 'line 2 second item'],
];
var_dump(str_replace('item', 'ITEM', $lines));