String.fromCharCode()

Baseline

20157

String.fromCharCode() UTF-16

console.log(String.fromCharCode(189, 43, 190, 61));
// : "+="

String.fromCharCode()
String.fromCharCode(num1)
String.fromCharCode(num1, num2)
String.fromCharCode(num1, num2, /* , */ numN)

num1, , numN: UTF-16 0 65535 (0xFFFF) 0xFFFF

N UTF-16 N

fromCharCode() String String String.fromCharCode()

Unicode 0 1114111 (0x10FFFF) charAt() 65536 16 65535 charAt(i) charAt(i + 1) 2 codePointAt(i) String.fromCodePoint() Unicode UTF-16 Unicode

fromCharCode() 16 \u String.fromCharCode(0xD83C, 0xDF03) \uD83C\uDF03 U+1F303 "Night with Stars" : 0x1f303: 0xd83c 0xdf03 String.fromCodePoint() String.fromCodePoint(0x1f303) U+1F303 "Night with Stars"

fromCharCode()

BMP UTF-16

String.fromCharCode(65, 66, 67); // "ABC" 
String.fromCharCode(0x2014); // "" 
String.fromCharCode(0x12014); //  "" 1 
String.fromCharCode(8212); //  "" 8212  0x2014  10

UTF-16 2

String.fromCharCode(0xd83c, 0xdf03); // Code Point U+1F303 "Night with
String.fromCharCode(55356, 57091); // Stars" === "\uD83C\uDF03"

String.fromCharCode(0xd834, 0xdf06, 0x61, 0xd834, 0xdf07); // "\uD834\uDF06a\uD834\uDF07"


ECMAScript 2027 LanguageSpecification # sec-string.fromcharcode

MDN

MDN 2025821

GitHub