RangeError: argument is not a valid code point
The JavaScript exception "Invalid code point" occurs when NaN values,
negative Integers (-1), non-Integers (5.4), or values larger than 0x10FFFF (1114111) are
used with String.fromCodePoint().
Message
RangeError: {0} is not a valid code point (Firefox)
RangeError: Invalid code point {0} (Chromium)
Error type
What went wrong?
String.fromCodePoint() throws this error when passed NaN
values, negative Integers (-1), non-Integers (5.4), or values larger than 0x10FFFF
(1114111).
A code point is a value in the
Unicode codespace; that is, the range of integers from 0 to
0x10FFFF.
Examples
Invalid cases
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
Valid cases
String.fromCodePoint(42); // "*"
String.fromCodePoint(65, 90); // "AZ"
String.fromCodePoint(0x404); // "\u0404"
String.fromCodePoint(0x2F804); // "\uD87E\uDC04"
String.fromCodePoint(194564); // "\uD87E\uDC04"
String.fromCodePoint(0x1D306, 0x61, 0x1D307) // "\uD834\uDF06a\uD834\uDF07"