How to convert from Hex to ASCII in JavaScript?

How to convert from Hex string to ASCII string in JavaScript?

Ex:

32343630 it will be 2460

3

9 Answers

function hex2a(hexx) { var hex = hexx.toString();//force conversion var str = ''; for (var i = 0; i < hex.length; i += 2) str += String.fromCharCode(parseInt(hex.substr(i, 2), 16)); return str;
}
hex2a('32343630'); // returns '2460'

3

Another way to do it (if you use Node.js):

var input = '32343630';
const output = Buffer.from(input, 'hex');
log(input + " -> " + output); // Result: 32343630 -> 2460

3

For completeness sake the reverse function:

function a2hex(str) { var arr = []; for (var i = 0, l = str.length; i < l; i ++) { var hex = Number(str.charCodeAt(i)).toString(16); arr.push(hex); } return arr.join('');
}
a2hex('2460'); //returns 32343630

3

You can use this..

var asciiVal = "32343630".match(/.{1,2}/g).map(function(v){ return String.fromCharCode(parseInt(v, 16)); }).join('');
document.write(asciiVal);

** for Hexa to String**

let input = '32343630';

Note : let output = new Buffer(input, 'hex'); // this is deprecated

let buf = Buffer.from(input, "hex");
let data = buf.toString("utf8");

4

I found a useful function present in web3 library.

var hexString = "0x1231ac"
string strValue = web3.toAscii(hexString)

Update: Newer version of web3 has this function in utils

The functions now resides in utils:

var hexString = "0x1231ac"
string strValue = web3.utils.hexToAscii(hexString)

2

I've found that the above solution will not work if you have to deal with control characters like 02 (STX) or 03 (ETX), anything under 10 will be read as a single digit and throw off everything after. I ran into this problem trying to parse through serial communications. So, I first took the hex string received and put it in a buffer object then converted the hex string into an array of the strings like so:

buf = Buffer.from(data, 'hex');
l = Buffer.byteLength(buf,'hex');
for (i=0; i<l; i++){ char = buf.toString('hex', i, i+1); msgArray.push(char);
}

Then .join it

message = msgArray.join('');

then I created a hexToAscii function just like in @Delan Azabani's answer above...

function hexToAscii(str){ hexString = str; strOut = ''; for (x = 0; x < hexString.length; x += 2) { strOut += String.fromCharCode(parseInt(hexString.substr(x, 2), 16)); } return strOut;
}

then called the hexToAscii function on 'message'

message = hexToAscii(message);

This approach also allowed me to iterate through the array and slice into the different parts of the transmission using the control characters so I could then deal with only the part of the data I wanted. Hope this helps someone else!

0

console.log(
"68656c6c6f20776f726c6421".match(/.{1,2}/g).reduce((acc,char)=>acc+String.fromCharCode(parseInt(char, 16)),"")
)

An optimized version of the implementation of the reverse function proposed by @michieljoris (according to the comments of @Beterraba and @Mala):

function a2hex(str) { var hex = ''; for (var i = 0, l = str.length; i < l; i++) { var hexx = Number(str.charCodeAt(i)).toString(16); hex += (hexx.length > 1 && hexx || '0' + hexx); } return hex;
}
alert(a2hex('2460')); // display 32343630

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