no-comma-dangle.md

规则名
no-comma-dangle

Disallows trailing commas in object and array literals.

(removed) This rule was removed in ESLint v1.0 and replaced by the comma-dangle rule.

Trailing commas in object literals are valid according to the ECMAScript 5 (and ECMAScript 3!) spec, however IE8 (when not in IE8 document mode) and below will throw an error when it encounters trailing commas in JavaScript.

var foo = {
    bar: "baz",
    qux: "quux",
};

规则详解

This rule is aimed at detecting trailing commas in object literals. As such, it will warn whenever it encounters a trailing comma in an object literal.

此规则的 错误 代码实例：

var foo = {
    bar: "baz",
    qux: "quux",
};

var arr = [1,2,];

foo({
  bar: "baz",
  qux: "quux",
});

此规则的 正确 代码实例：

::: correct

var foo = {
    bar: "baz",
    qux: "quux"
};

var arr = [1,2];

foo({
  bar: "baz",
  qux: "quux"
});

禁用建议

If your code will not be run in IE8 or below (a Node.js application, for example) and you'd prefer to allow trailing commas, turn this rule off.