how to find and replace in the first word from the string in php

Question

how to find and replace the first word from the string using php

eg:

 $str = 'Super World Hello World';
 replace($str,'Hello','Hi');

expected result should be 'Super World Hello World' as it does not match with first word.

eg2:

 $str = 'Hello World Hello World';
 replace($str,'Hello','Hi');

expected result should be 'Hi World Hello World' as it does match with first word.

please help

https://www.w3resource.com/php-exercises/php-string-exercise-10.php — IcedAnt, Mar 14 '18 at 18:39
Possible duplicate of [Using str\_replace so that it only acts on the first match?](https://stackoverflow.com/questions/1252693/using-str-replace-so-that-it-only-acts-on-the-first-match) — Nikhil G, Mar 14 '18 at 18:43
Thanks, i have updated my question, my second case it fails. — Thavaprakash Swaminathan, Mar 14 '18 at 18:46

score 0 · Accepted Answer · answered Mar 14 '18 at 18:58

Create a function for this, passed 3 arguments. Logic is convert string into array by explode() function and get first element of the array by using array_shift() function and compare with search string

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);

Demo

how to find and replace in the first word from the string in php

1 Answers1