Javascript unicode to ASCII

Question

Need to convert the unicode of the SOH value '\u0001' to Ascii. Why is this not working?

var soh = String.fromCharCode(01);
It returns '\u0001'
Or when I try

var soh = '\u0001' It returns a smiley face.
How can I get the unicode to become the proper SOH value(a blank unprintable character)

Answer 1

JS has no ASCII strings, they're intrinsically UTF-16.

In a browser you're out of luck. If you're coding for node.js you're lucky!

You can use a buffer to transcode strings into octets and then manipulate the binary data at will. But you won't get necessarily a valid string back out of the buffer once you've messed with it.

Either way you'll have to read more about it here:

https://mathiasbynens.be/notes/javascript-encoding

or here:

https://nodejs.org/api/buffer.html

---

EDIT: in the comment you say you use node.js, so this is an excerpt from the second link above.

const buf5 = Buffer.from('test');
// Creates a Buffer containing ASCII bytes [74, 65, 73, 74].

To create the SOH character embedded in a common ASCII string use the common escape sequence\x01 like so:

const bufferWithSOH = Buffer.from("string with \x01 SOH", "ascii");

This should do it. You can then send the bufferWithSOH content to an output stream such as a network, console or file stream.

Node.js documentation will guide you on how to use strings in a Buffer pretty well, just look up the second link above.