Converts a string to an octal and hexadecimal escape sequence.
Escape sequence type:

Sometimes you need to change the code so that it is difficult to understand what it does. For example, you are a web developer, handing over a project to a customer, but you are afraid that he may not pay. Then you can embed code on the site that, for example, will give you access to create/change/delete files on the client server. But this code needs to be disguised somehow. For such purposes, using the Hex-Oct encoder, you can convert some pieces of code into an escape sequence.

For example, $_SERVER["DOCUMENT_ROOT"] can be converted to $_SERVER["\104\117\103\x55\115\x45\116\124\x5f\x52\x4f \x4f\124"] and it will be the same.

Here is a more interesting example:
$a = "\143\162\x65\141\164\145\137\146\x75\156\x63\164\ x69\x6f\156";
$a('$c', "\x65\143\x68\x6f\x20\x24\143\x3b< /span>")("\x68\x65\x6c\x6c\x6f\40\167\157\x72\x6c\x64\x21");
This code will display "hello world!" on the page.