php - str_replace 2 parts with 2 different results - php

Question

I want to add some html to a word based on the words in a compound word.
For instance let's take the word "doghouse'
Let's say
$row2['word'] = 'doghouse';
$word = 'dog';
$otherword = 'house';
I want the end result to produce
<span style="color:blue">dog</span><span style="color:red">house</span>
My code so far that does not work (which I thought I could array the replace in str_replace but apparently I can't.
$finalword = str_replace(array($word,$otherword),array("<span style='color:blue'>".$word."</span>","<span style='color:red'>".$word."</span>"),$row2['word']);
Is str_replace the wrong choice for this?

Answer 1

str_replace is the correct function, but you're not really using it correctly. The way you've set it up, $row2 would have to be an array, but it's not, it's a string. So you need to use an alternate approach. Your code should look like this:
str_replace($row2, $word.$otherword, "<span style='color:blue'>".$word."</span><span style='color:red'>".$otherword."</span>");
The first term ($row2) is where you're searching, what php calls the 'haystack'. The second term $word.$otherword is what you're searching for (the 'needle'). The third term is what you replace the 'needle' with when you find it.

Answer 2

I don't know how do you store your colors, but does it work for you?
$row2['word'] = 'doghouse';
$words = array('dog','house');
$colors = array('blue', 'red');
$finalword = "";
for ($i = 0; $i < count($words); $i++) {
$finalword .= "<span style='color:".$colors[$i]."'>".$words[$i]."</span>";
}
echo $finalword;