如何使用 angular 获取数组中对象的索引? [英] How do I get the index of object in array using angular?

问题描述

我需要在数组中有一个对象的索引，以便我可以删除数组的这一部分.我试过用这个:

I need to have the index of an object in array so I can delete this part of the array. I tried using this:

var index = this.urenRegistratie.indexOf(newDatum);

但它一直返回-1，我不知道为什么会这样.

But it keeps returning -1 and I don't know why this is happening.

这是我拥有的代码的一部分.它从 html 的表单中获取数据并将其放入我的数组中，现在我已经准备好了 if 语句( exisitingDatum )，我的代码需要在那里.有人可以帮我一下吗?

this is the part of the code I have. it gets data out of a form in html and places that into my array, now I already have an if statement ready ( exisitingDatum ) , my code needs to be in there. Can someone please help me out a bit?

 store(newValue:number, newDatum, newAanwezig, newComment){
    const existingDatum = this.urenRegistratie.find(billable => {
      return billable.datum === newDatum;
      return
    });

    if (!existingDatum) {
        let billable = new BillableHours();
        billable.datum = newDatum;
        billable.hours = +newValue;
        billable.aanwezig = newAanwezig;
        billable.comment = newComment;

        if(billable.aanwezig == "Aanwezig" && billable.hours !== 0 && billable.datum !== null) {
          this.urenRegistratie.push(billable);
        }
    }

    if(existingDatum) {

    }

  }

推荐答案

正如 mdn 所说:

findIndex() 方法返回第一个元素的索引满足提供的测试函数的数组.否则，它返回-1，表示没有元素通过测试.

The findIndex() method returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1, indicating that no element passed the test.

如果你有这样的对象数组，那么尝试使用findIndex:

If you have array of objects like this, then try to use findIndex:

const a = [
    { firstName: "Adam", LastName: "Howard" },
    { firstName: "Ben", LastName: "Skeet" },
    { firstName: "Joseph", LastName: "Skeet" }
];

let index = a.findIndex(x => x.LastName === "Skeet");
console.log(index);

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