Javascript: UTF8 ↔ String & UTF8 ↔ base64

Fucntion to convert to UTF8 byte array:

	function toUTF8Array(str) {
	var utf8 = [];
	for (var i=0; i < str.length; i++) {
	var charcode = str.charCodeAt(i);
	if (charcode < 0x80) utf8.push(charcode);
	else if (charcode < 0x800) {
	utf8.push(0xc0 \| (charcode >> 6),
	0x80 \| (charcode & 0x3f));
	}
	else if (charcode < 0xd800 \|\| charcode >= 0xe000) {
	utf8.push(0xe0 \| (charcode >> 12),
	0x80 \| ((charcode>>6) & 0x3f),
	0x80 \| (charcode & 0x3f));
	}
	// surrogate pair
	else {
	i++;
	// UTF-16 encodes 0x10000-0x10FFFF by
	// subtracting 0x10000 and splitting the
	// 20 bits of 0x0-0xFFFFF into two halves
	charcode = 0x10000 + (((charcode & 0x3ff)<<10)
	\| (str.charCodeAt(i) & 0x3ff))
	utf8.push(0xf0 \| (charcode >>18),
	0x80 \| ((charcode>>12) & 0x3f),
	0x80 \| ((charcode>>6) & 0x3f),
	0x80 \| (charcode & 0x3f));
	}
	}
	return utf8;
	}

view raw

toUTF8Array.js

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Function to convert from UTF8 byte array to String:

JavaScript: Correctly Converting a Byte Array to a UTF-8 String

For base64: