Errors: Not a codepoint
Errors: Not a codepoint
信息
RangeError: {0} is not a valid code point (Firefox)
RangeError: Invalid code point {0} (Chrome)
错误类型
RangeError
哪里出错了?
String.fromCodePoint()这个方法只能接受有效的码位（code point） 。
码位（ code point）是组成码空间（或代码页）的数值，范围是 0 到 0x10FFFF。
NaN，负整数（-1），非整数（3.14），或编号大于0x10FFFF (1114111) 的字符，无法使用该方法。
示例
无效的情况
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
有效的情况
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"
