Question

首先看看下面的简单代码：

function mySecondFunction(objArray,setFunc)
{
    for (let i = 0; i < objArray.length; i++)
    {
        objArray[i].info.setTop(72);
    }
}

function myFunction()
{
    let myObjArray = [];
    for (let i = 0; i < 10; i++)
    {
    myObjArray.push({
        info:{topVar:0,
          bottomVar:0,
          get top() {return this.topVar;},
          get bottom() {return this.bottomVar;},
          setTop: function(input) {this.topVar = input;},
          setBottom: function(input) {this.bottomVar = input; }
         }
    });
    }
    mySecondFunction(myObjArray); // This works Fine
    mySecondFunction(myObjArray,setTop); // I want something like this!!!
}

如您所见，我想将对象的方法传递给另一个函数。我知道很多可能的解决方案来避免这种情况，但我想知道它是否可能。

Answer 1

分离并传递作为参数。请务必使用call设置预期的this值。

function mySecondFunction(objArray, setFunc)
{
    for (let i = 0; i < objArray.length; i++)
    {
        setFunc.call(objArray[i].info, 72); 
        /* explicitly telling that: 
        please set 'this' value in this function to be 'objArray[i].info' when running, 
        allowing, e.g. `this.topVar` in 
        `setTop: function(input) {this.topVar = input;}` 
        to be operating on `objArray[i].info.topVar` */
    }
}

function myFunction()
{
    let myObjArray = [];
    for (let i = 0; i < 10; i++)
    {
    myObjArray.push({
        info:{topVar:0,
          bottomVar:0,
          get top() {return this.topVar;},
          get bottom() {return this.bottomVar;},
          setTop: function(input) {this.topVar = input;},
          setBottom: function(input) {this.bottomVar = input; }
         }
    });
    }
    mySecondFunction(myObjArray, myObjArray[0].info.setTop); 
    /* once detaching the method from the object, 
    (if we are not using arrow functions), 
    we lose 'this' value, meaning we are losing 
    the target of object that we want to operate on */
    
    console.log(myObjArray)
}

myFunction();

Answer 2

您可以在数组列表中定位项目编号。您可以静态地（即1 - ???）或动态地使用迭代和变量。然后你可以在其中的对象属性。例如：

myObjArray[0].info.setTop

这将针对数组中的第一项。传递方法时一定要省略括号（()），因为你想传递函数参考而不是结果

如何将对象的方法作为参数传递给Javascript

2 个答案: