Preg_replace Substitution value has sub-expression value plus numerical value related issues

Preg_replace Substitution value has sub-expression value plus numeric problem
This post was last edited by Panlvfei on 2014-04-02 15:31:02

A simple replacement as follows:
$ih = 100;
$aa = ' a123b ';
$aa =preg_replace ('/^ (a) 123 (b) $/i ', ' $ ' $ih. ' $ ', $AA);
Print_r ($AA);
How the result is wrong, $ih into the letter is normal, the number will be lost first and $ $. It's normal to add a letter in $, it's not my computer problem, is it?
------Solution--------------------

$aa =preg_replace ('/^ (a) 123 (b) $/ie ', ' "$". $ih. " $ "', $AA);

------Solution--------------------

$ih = 500;
$aa = ' a123b ';
$aa =preg_replace ('/^ (a) 123 (b) $/i ', ' ${1} '. $ih. ' ${2} ', $AA);
Print_r ($AA);

