How do I encode a JavaScript string in utf-16?

Question

In Python 3, I can do this:

>>> "13,56ドル".encode('utf-16')
b'\xff\xfe\xac 1\x003\x00,\x005\x006\x00'

The input is a (unicode) string, while the output is a sequence of raw bytes of that string encoded in utf-16.

How can I do the same in JavaScript - go from a (unicode) string, to a sequence of raw bytes (perhaps as a Uint8Array?) of that string encoded in utf-16?

• phuzi: Possible duplicate of How to convert a String to Bytearray

Answer 1

Do you want this?

function strEncodeUTF16(str) {
 var buf = new ArrayBuffer(str.length*2);
 var bufView = new Uint16Array(buf);
 for (var i=0, strLen=str.length; i < strLen; i++) {
 bufView[i] = str.charCodeAt(i);
 }
 return bufView;
}
var arr = strEncodeUTF16('13,56ドル');

Taken from Google Developers

• Clifford Fajardo: I used this to convert a utf8 string (nodejs's default encoding in most cases), into utf16 string (which is the type of default encoding for javascript strings).

Answer 2

function strEncodeUTF16(str) {
 var arr = []
 for (var i = 0; i < str.length; i++) {
 arr[i] = str.charCodeAt(i)
 }
 return arr
}
var arr = strEncodeUTF16('13,56ドル');
console.log(arr)

Answer 3

I needed to convert a utf8 encoded string to a hexadecimal utf-16 string:

function dec2hex(dec, padding){
 return parseInt(dec, 10).toString(16).padStart(padding, '0');
}
function utf8StringToUtf16String(str) {
 var utf16 = [];
 for (var i=0, strLen=str.length; i < strLen; i++) {
 utf16.push(dec2hex(str.charCodeAt(i), 4));
 }
 return utf16.join();
}

Answer 4

To get Uint8Array, use this code

inspired by shilch's Answer

change return bufView to return new Uint8Array(buf)

---

function strEncodeUTF16(str) {
 var buf = new ArrayBuffer(str.length * 2);
 var bufView = new Uint16Array(buf);
 for (var i = 0, strLen = str.length; i < strLen; i++) {
 bufView[i] = str.charCodeAt(i);
 }
 return new Uint8Array(buf);
}
var arr = strEncodeUTF16('13,56ドル');