no-param-reassign

不允许重新分配 function 参数

对声明为函数参数的变量赋值可能会产生误导并导致行为混乱，因为修改函数参数也会改变 arguments 对象。通常，分配给函数参数是无意的，并且表示错误或程序员错误。

此规则也可以配置为在修改函数参数时失败。对参数的副作用可能会导致违反直觉的执行流程并使错误难以追踪。

规则详情

此规则旨在防止因修改或重新分配函数参数而导致的意外行为。

此规则的错误代码示例：

/*eslint no-param-reassign: "error"*/

function foo(bar) {
    bar = 13;
}

function foo(bar) {
    bar++;
}

function foo(bar) {
    for (bar in baz) {}
}

function foo(bar) {
    for (bar of baz) {}
}

DzO9VpSFHJiTjGCgt1KSooNhAIn1o64th84QTOygwWSy7fBgj4TGxtI1vaW0J9Ta

/*eslint no-param-reassign: "error"*/

function foo(bar) {
    var baz = bar;
}

选项

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props

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/*eslint no-param-reassign: ["error", { "props": false }]*/

function foo(bar) {
    bar.prop = "value";
}

function foo(bar) {
    delete bar.aaa;
}

function foo(bar) {
    bar.aaa++;
}

function foo(bar) {
    for (bar.aaa in baz) {}
}

function foo(bar) {
    for (bar.aaa of baz) {}
}

e1gy3cxJmCdWe+dm90ZS/dV/dL4EYEumJs/4xvQE083l4RZ/5tm3W91znd+gkQjtDyPI0a/sBR4iu42TdjY/zQ==

/*eslint no-param-reassign: ["error", { "props": true }]*/

function foo(bar) {
    bar.prop = "value";
}

function foo(bar) {
    delete bar.aaa;
}

function foo(bar) {
    bar.aaa++;
}

function foo(bar) {
    for (bar.aaa in baz) {}
}

function foo(bar) {
    for (bar.aaa of baz) {}
}

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/*eslint no-param-reassign: ["error", { "props": true, "ignorePropertyModificationsFor": ["bar"] }]*/

function foo(bar) {
    bar.prop = "value";
}

function foo(bar) {
    delete bar.aaa;
}

function foo(bar) {
    bar.aaa++;
}

function foo(bar) {
    for (bar.aaa in baz) {}
}

function foo(bar) {
    for (bar.aaa of baz) {}
}

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/*eslint no-param-reassign: ["error", { "props": true, "ignorePropertyModificationsForRegex": ["^bar"] }]*/

function foo(barVar) {
    barVar.prop = "value";
}

function foo(barrito) {
    delete barrito.aaa;
}

function foo(bar_) {
    bar_.aaa++;
}

function foo(barBaz) {
    for (barBaz.aaa in baz) {}
}

function foo(barBaz) {
    for (barBaz.aaa of baz) {}
}

何时不使用

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