I saw a Javascript function that starts like this:
var _0xadf3 = function(_0x29ae0e, _0x3626db) {
_0x29ae0e = _0x29ae0e - 0x0;
var _0x5edbe5 = _0x4430[_0x29ae0e];
if (_0xadf3['ogYkVt'] === undefined) {
(function() {
What is the purpose of the first line of code (_0x29ae0e = _0x29ae0e - 0x0;)? The first line of code takes the first variable of the function, _0x29ae0e, and subtracts 0 from it. Thus, it seems that you will just be left with the original value. This seems unnecessary, and I would like to understand the reason.
Subtracting by zero is a way to force type-conversion. From Type-Conversion tutorial
Any mathematical operator except the concatenation/addition operator will force type-conversion. So conversion of a string to a number might entail performing a mathematical operation on the string representation of the number that would not affect the resulting number, such as subtracting zero or multiplying by one.
Subtracting by 0x0 in this case performs a forced type-conversion on _0x29ae0e to convert it to hex