php - How to Split Codeigniter pseudo variables

one text

Solution:

If I understand correctly, memory_usage will return "2.26MB" and you want "2.26". If you know that the unit will always be 2 characters you could do it like this:

$mem = "2.26MB";
substr($mem, -2); // returns "2.26"

In your example:

substr($mem, 0, -2);

You are setting the offset position to 0 in the second argument, which starts the substring at the beginning of $mem, then you are creating a substring that is -2 characters in length.