substitutions string php module 2 - php

Question

I have an array with several elements like this:
cars = array ("name" => "volkswagen", "description" => "hier by hidd by hisd by hidf by"
"name" => "fiat", "description" => "hier by hias by hisad by hiasd by");
how could replace elements in each array in each two occurrences description by half. That is the result:
carsModified = array ("name" => "volkswagen", "description" => "hier by hidd replace hisd by hidf replace"
"name" => "fiat", "description" => "hier by hias replace hisad by hiasd replace");
by substitutions for replace.

Answer 1

If I understood correctly, you have an array of the following format:
$arr = array (
array(
"name" => "volkswagen",
"description" => "hier by hidd by hisd by hidf by"
),
array(
"name" => "fiat",
"description" => "hier by hias by hisad by hiasd by"
)
);
Now, you want to modify the description field (or any other), which contains the word "by" with the word "replace". You want to replace only the even occurrences. For this, we will write a function that accepts a string and replaces every second occurrence of a string. There are many ways to do it, this is one:
function replace_evens($search, $replace, $subject){
$parsed = explode($search, $subject);
$doubles = array();
for ($i=0, $n=count($parsed); $i<$n-1; $i+=2){
$doubles[] = $parsed[$i] . $search .$parsed[$i+1];
}
if ($i==$n-1) $doubles[] = $parsed[$n-1];
return implode($replace, $doubles);
}
Now we will iterate over the array, and foreach element (which is also an array) we will go over all of it's fields. Notice the reference (&) before $a because we want to modify the same element and not clone it. Also notice that we append spaces around the value $v
foreach($arr as &$a){
foreach($a as $k=>$v){
$a[$k] = trim(replace_evens(' by ', ' replace ' , ' ' . $v. ' ' ));
}
}
print_r($arr);
Hope it helps. Take in mind that I did not test this code...