将全局变量传递给函数 [英] Passing a global variable to a function

问题描述

为什么以下代码给我0而不是1？我希望我的函数更改在函数外声明的变量，但我不想在函数声明中指定变量。

How come the following code is giving me a 0 instead of a 1? I want my function to change a variable declared outside the function but I do not want to specify the variable in the function declaration.

that = 0;

function go(input) {
    input++;
}

go(that);

console.log(that);

推荐答案

正如Oriol所回答，它不起作用，因为变量按值传递，因此您不会更改that变量。解决方法是传递变量名称：

As answered by Oriol, it doesn't work because the variable is passed by value, so you're not changing the "that" variable. A workaround would be to pass the variable name :

that = 0;

function test(input) {
    window[input]++;
}

test("that");

console.log(that); // 1

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