语法错误：不推荐使用以 "0" 为前缀的八进制文字

¥Message

SyntaxError: Octal literals are not allowed in strict mode. (V8-based)
SyntaxError: Decimals with leading zeros are not allowed in strict mode. (V8-based)
SyntaxError: Unexpected number (V8-based)
SyntaxError: "0"-prefixed octal literals are deprecated; use the "0o" prefix instead (Firefox)
SyntaxError: Decimal integer literals with a leading zero are forbidden in strict mode (Safari)

¥Error type

仅限 严格模式 中的 SyntaxError。

¥SyntaxError in strict mode only.

¥What went wrong?

八进制文字已弃用。当你在十进制整数前面加上 0 时，你实际上会将其更改为八进制文字，这可能令人惊讶。标准化语法使用前导零，后跟小写或大写拉丁字母 "O"（0o 或 0O）。

¥Octal literals are deprecated. When you prefix a decimal integer with 0, you actually change it to an octal literal, which may be surprising. The standardized syntax uses a leading zero followed by a lowercase or uppercase Latin letter "O" (0o or 0O).

前导零始终是被禁止的，即使文字不是有效的八进制文字语法（例如文字包含数字 8 或 9，或者它有小数点）。数字文字只能以 0 开头，如果 0 是其单位位。

¥Leading zeros are always forbidden, even when the literal is not valid octal literal syntax (such as when the literal contains the digits 8 or 9, or it has a decimal point). A number literal may only start with 0 if that 0 is its units place.

¥Examples

¥"0"-prefixed octal literals

"use strict";

03;

// SyntaxError: "0"-prefixed octal literals are deprecated; use the "0o" prefix instead

¥Valid octal numbers

使用前导零后跟字母 "o" 或 "O"：

¥Use a leading zero followed by the letter "o" or "O":

0o3;

¥See also

• 词汇语法