JS: String.fromCharCode

String.fromCharCode(codeUnit1, codeUnit2, etc)

Return a string, where each character in string has corresponding String Code Unit .

Each of codeUnit should be a integer from 0 to 65535 inclusive. (Note: 65535 = 2^16 -1). If it is greater than 65535, a value of modulo(codeUnit, 2^16) is used.

// convert sequence of unicode codepoint to string

console.log(String.fromCharCode(97, 98) === "ab");

// 97 is the codepoint for letter a
// 98 is the codepoint for letter b

// String.fromCharCode won't work as expected if codepoint is greater than 65535 (that's 2^16 )

const xx = String.fromCharCode(128514);

const yy = String.fromCharCode(62978);

console.log(xx === yy);

console.log((xx === "😂") === false);

console.log((128514 % (2 ** 16)) === 62978);

// 😂
// name: FACE WITH TEARS OF JOY
// codepoint decimal: 128514
// codepoint hexadecimal: 1f602