Question

I want to replace { by {{} and } by {}}, because, I need to escape those { & } with {}.
if I’ve as input {blah} I want my script to output {{}blah{}}, see?
But it is not working look at what I did

$output = str_replace(array("}", "{"), array("{}}", "{{}"), '{blah}');

But as output I got this : {{}blah{{}}} instead of {{}blah{}}

Answer 1

PHP iterates the whole string for each array item you put in the $search parameter.

It is in fact replacing '{blah}' into '{blah{}}' with your first array item '{', and then from that into '{{}blah{{}}}' because there is another '{' after the first replacement.

You better off doing this with regular expression, with a single RegExp pattern it will run only once in your input string.

$str = preg_replace('/(\{|\})/', '{\\1}', '{blah}');