- array_shift: documentation ( source)
- implode: documentation ( source)
- explode: documentation ( source)
<?php
function getReplacedStr($str, $searchStr, $replaceWith){
$arr = explode(' ', $str);
$firstElement = array_shift($arr);
if($searchStr == $firstElement){
$finalStr = $replaceWith.' '.implode(' ', $arr);
}else{
$finalStr = $str;
}
return $finalStr;
}
$replaceWith = 'Hi';
$searchStr = 'Hello';
$str = 'Hello World Hello World';
$str2 = 'Super World Hello World';
echo getReplacedStr($str, $searchStr, $replaceWith);
echo "\n";
echo getReplacedStr($str2, $searchStr, $replaceWith);