将值传递给特定参数而无需关心参数的位置 [英] Pass a value to a specific parameter without caring about the position of the parameter

问题描述

我想知道是否可以通过例如指定其名称来将值传递给特定参数，而不考虑该参数是第一个，第二个还是第100个.

I was wondering if it is possible to pass a value to a specific parameter by for example specifying its name, not taking into account if this parameter is the first, the second or the 100th one.

例如，在Python中，您可以像这样轻松地做到这一点:

For example, in Python you can do it easily like:

def myFunction(x, y):
    pass

myFunction(y=3);

我真的需要将值传递给特定参数，但我不确定该值在参数枚举中的位置.我搜索了一段时间，但似乎没有任何作用.

I really need to pass a value to a specific parameter of which I don't know necessarily its position in the parameters enumeration. I have searched around for a while, but nothing seems to work.

推荐答案

否，javascript中不存在命名参数.

No, named parameters do not exist in javascript.

有一个(多种)解决方法，通常一个复杂的方法可能会用一个对象代替单个参数

There is a (sort of) workaround, often a complex method may take an object in place of individual parameters

function doSomething(obj){
   console.log(obj.x);
   console.log(obj.y);
}

可以用

doSomething({y:123})

首先记录undefined(x)，然后记录123(y).

Which would log undefined first (the x) followed by 123 (the y).

您也可以允许某些参数为可选参数，并在未提供的情况下提供默认值:

You could allow some parameters to be optional too, and provide defaults if not supplied:

function doSomething(obj){
   var localX = obj.x || "Hello World";
   var localY = obj.y || 999;
   console.log(localX);
   console.log(localY);
}

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