converting hexadecimal escape chars to binary

Question

I'm looking for a way to uniformly convert JavaScript chars to binary. One problem that I'm facing is that I'm not able to convert strings used in unescape function correctly

document.write("HI"); ==> HI (case 1)
document.write("\x48\x49");  ==> HI (case 2)
document.write(unescape("%48%49")); ==> HI (case 3)

Case 1: Converting "HI" to binary generates:

0100100001001001

Case 2: Converting "\\x48\\x49" to binary generates:

0100100001001001

Case 3: Converting "%48%49" to binary generates:

001001010011010000111000001001010011010000111001

I understand what is happening in case 3. it converts each char to binary without realizing that these chars are in hex representation. I'm wondering if there is a way to make case 3 have the same binary representation as case 1 and case 2 without any pre-processing required?

Ie, is there a function either in JavaScript, Python or any other language that can realize that "%48" is one char represented in hex and is able to convert it to binary?

Answer 1

The decodeURIComponent is the right function for this. The decode function is deprecated. Here is an example.

If you put %48%49 in the input and click on the 'Convert' button, it gives you the second case.

 var test = document.querySelector("#test"); var btn = document.querySelector("#btn"); var result = document.querySelector("#result"); btn.addEventListener("click", function() { var value = decodeURIComponent(test.value); var resultText = ""; for (i = 0; i < value.length; i++) { resultText += value.charCodeAt(i).toString(2); } result.innerText = resultText; }); 

 <input type="text" id="test"> <button id="btn">Convert</button> <p id="result"></p>