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SyntaxError: identifier starts immediately after numeric literal

当标识符以数字开头时，JavaScript 会出现“identifier starts immediately after numeric literal”的异常。标识符只能以字母、下划线（_）或美元符号（$）开头。

本文内容

错误信息

SyntaxError: Unexpected identifier after numeric literal (Edge) SyntaxError: identifier starts immediately after numeric literal (Firefox) SyntaxError: Unexpected number (Chrome)

错误类型

SyntaxError

什么地方出错了？

变量的名称（也称为标识符）需遵循特定的规则，而这些规则是你的代码必须遵循的！

JavaScript 标识符必须以字母、下划线（_）或美元符号（$）开头。不能以数字开头！只有后续的字符可以是数字（0-9）。

示例

以数字文字开头的变量名

在 JavaScript 中，变量名不能以数字开头。以下表达式会失败：

js
const 1life = "foo"; // SyntaxError: identifier starts immediately after numeric literal const foo = 1life; // SyntaxError: identifier starts immediately after numeric literal alert(1.foo); // SyntaxError: identifier starts immediately after numeric literal

你需要重新命名变量以避免前导数字。

js
const life1 = "foo"; const foo = life1;

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