Replace characters with word in PHP? - php

Question

Want to replace specific letters in a string to a full word.
I'm using:
function spec2hex($instr) {
for ($i=0; $i<strlen($instr); $i++) {
$char = substr($instr, $i,1);
if ($char == "a"){
$char = "hello";
}
$convString .= "&#".ord($char).";";
}
return $convString;
}
$myString = "adam";
$convertedString = spec2hex($myString);
echo $convertedString;
but that's returning:
hdhm
How do I do this? By the way, this is to replace punctuation with hex characters.
Thanks all.

Answer 1

Use http://php.net/substr_replace
substr_replace($instr, $word, $i,1);

Answer 2

ord() expects only a SINGLE character. You're passing in hello, so ord is doing its thing only on the h:
php > echo ord('hello');
104
php > echo ord('h');
104
So in effect your output is actually
hdhm

Answer 3

it you want to use your same code just change $convString .= "&#".ord($char).";";
to $convString .= $char;

Answer 4

If you just want to replace the occurrence of a with hello within the string you pass to the function, why not use PHP's str_replace()?
function spec2hex($instr) {
return str_replace("a","hello",$instr);
}

Answer 5

I must assume that you don't want to have hex characters instead of punctuation but html entities. Be aware that str_replace(), when called with arrays, will run over the string for multiple times, thus replacing the ";" in "{" also!
Your posted code is not useful for replacing punctuation.
use strtr() with arrays, it doesn't have the drawback of str_replace().
$aReplacements = array(',' => ',', '.' => '.'); //todo: complete the array
$sText = strtr($sText, $aReplacements);