如何在不设置全局变量的情况下确定函数是否已被调用 [英] How to determine if a function has been called without setting global variable

问题描述

我正在寻找一种很好的技术来摆脱我想做的事情:设置全局变量.

I am looking for a good technique to get away from what I am tempted to do: to set a global variable.

第一次有人通过单击按钮来运行功能时，会触发一个初始功能，将一些东西变成可拖动对象.以后，如果他们第二次单击按钮，我想确定init函数是否已初始化，如果不是，则不要再次调用它.我可以通过在init函数中设置一个全局变量，然后从click函数中检查该变量来轻松地做到这一点，但是我想知道如何在不设置全局变量的情况下做到这一点.我真的很想举个例子.

The first time someone runs a function by clicking a button it triggers an initial function to turn a few things into draggables. Later, if they click the button a second time I want to determine if the init function has been initialized, and if so to not call it again. I could easily do this by setting a global variable from the init function and then checking that variable from the click function, but I'm wondering how to do this without setting a global variable. I would really like an example of a way to do this.

推荐答案

您可以向该函数添加属性:

You could add a property to the function:

function init() {
    init.called = true;
}

init();

if(init.called) {
    //stuff
}

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