String.fromCodePoint()

num1, ..., numN

A sequence of code points.

A string created by using the specified sequence of code points.

RangeError

Thrown if an invalid Unicode code point is given.

This method returns a string (and not a String object).

Because fromCodePoint() is a static method of String, you must call it as String.fromCodePoint(), rather than as a method of a String object you created.

Valid input:

String.fromCodePoint(42); // "*"
String.fromCodePoint(65, 90); // "AZ"
String.fromCodePoint(0x404); // "\u0404" === "Є"
String.fromCodePoint(0x2f804); // "\uD87E\uDC04"
String.fromCodePoint(194564); // "\uD87E\uDC04"
String.fromCodePoint(0x1d306, 0x61, 0x1d307); // "\uD834\uDF06a\uD834\uDF07"

Invalid input:

String.fromCodePoint("_"); // RangeError
String.fromCodePoint(Infinity); // RangeError
String.fromCodePoint(-1); // RangeError
String.fromCodePoint(3.14); // RangeError
String.fromCodePoint(3e-2); // RangeError
String.fromCodePoint(NaN); // RangeError

String.fromCharCode() cannot return supplementary characters (i.e. code points 0x010000 – 0x10FFFF) by specifying their code point. Instead, it requires the UTF-16 surrogate pair in order to return a supplementary character:

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

String.fromCodePoint(), on the other hand, can return 4-byte supplementary characters, as well as the more common 2-byte BMP characters, by specifying their code point (which is equivalent to the UTF-32 code unit):

String.fromCodePoint(0x1f303); // or 127747 in decimal

• Polyfill of String.fromCodePoint in core-js
• String.fromCharCode()
• String.prototype.charAt()
• String.prototype.codePointAt()
• String.prototype.charCodeAt()