how to replace a placeholder in a string?

Question

Not very sure how to word this question but I\'ll give an example.

$string = \'Hey, $name. How are you?\'; 

When I post this string,

Answer 1

I've always been a fan of strtr.

$ php -r 'echo strtr("Hi @name. The weather is @weather.", ["@name" => "Nick", "@weather" => "Sunny"]);'
Hi Nick. The weather is Sunny.

The other advantage to this is you can define different placeholder prefix types. This is how Drupal does it; @ indicates a string to be escaped as safe to output to a web page (to avoid injection attacks). The format_string command loops over your parameters (such as @name and @weather) and if the first character is an @, then it uses check_plain on the value.