如何从JavaScript中的另一个数组中删除数组

Question

0: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}
1: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}
2: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}

我要删除数组中的0:{}个数组。我该如何删除？以及如何找到第一项的价值？

Answer 1

由于数组的第一个元素始终是索引0，因此可以使用Array.prototype.shift删除第一个元素：

const array = [{
  id: 1553825061863,
  name: "Thai Milk Tea",
  qty: "1",
  total_amount: 9500,
  toppings: 500
}, {
  id: 1553825061863,
  name: "Thai Milk Tea",
  qty: "1",
  total_amount: 9500,
  toppings: 500
}, {
  id: 1553825061863,
  name: "Thai Milk Tea",
  qty: "1",
  total_amount: 9500,
  toppings: 500
}];

let remainingArray = array;
remainingArray.shift();

console.log(remainingArray);

.as-console-wrapper {
  max-height: 100% !important;
  top: auto;
}

Answer 2

可以有多种方法。

使用shift()

let arr = [{id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}]

arr.shift();
console.log(arr);

注意：shift()将修改原始数组。

使用splice()

let arr = [{id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}]

arr.splice(0,1);
console.log(arr);

注意：splice()将修改原始数组。

使用slice

let arr = [{id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}]

let res = arr.slice(1)
console.log(res);

使用传播算子和销毁分配

let arr = [{id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}, {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500}]

const [,...rest] = arr
console.log(rest);

Answer 3

据我从您的问题中了解到，您有类似下面的内容，必须从Array1中删除Array2，

Array1 = 0: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}
         1: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}
         2: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}

Array2 = 0: {id: 1553825061863, name: "Thai Milk Tea", qty: "1", total_amount: 9500, toppings: 500, …}

如果是这样，请使用过滤器功能尝试以下操作。

    var data = Array1; 
    var selectedRows = Array2; 

    var unSelectedRows = [];
    var unSelectedRows = data.filter( function( el ) {
      return !selectedRows.includes( el );
    } );

您可以在unSelectedRows数组中获得第1个和第2个元素。

Answer 4

//try this on your console. You can use the shift operator to shift the first element.
//also to remove the last element use pop
>>var myArr = [{id : 1, name: "A"}, {id: 2, name: "B"}, {id:3, name: "C"}];
undefined
>>myArr.shift(0);
{id: 1, name: "A"}
>>myArr
0: {id: 2, name: "B"}
1: {id: 3, name: "C"}

这是有关Array.protoType.shift（）的详细链接 删除第一个元素：

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift

Answer 5

使用以下方法从数组中删除一个数组索引的简单方法

var ar = ['zero', 'one', 'two', 'three'];
ar.shift(); // returns "zero"
console.log( ar );

如果是这样的数组，则可以使用以下命令删除0索引。

var ar = [
            {  id: 155382506003,  toppings: 500}, 
            {  id: 155382506002,  toppings: 100},
            {  id: 155382506001,  toppings: 200}
            ];
  ar.shift();
console.log( ar );

Answer 6

您有一个Javascript对象数组。您可以通过以下方式删除第一个元素：

使用shift函数，例如：

var first = fruits.shift(); // remove Apple from the front

例如，使用splice函数-通过索引位置删除元素：

var removedItem = fruits.splice(pos, 1); // this is how to remove an item

您可以按索引访问元素的值，例如：

var first = fruits[0];

您可以使用foreach查找字段的值，例如：

fruits.forEach(function(item, index, array) {
    if (item.id === 1553825061863) {
        console.log(item, index);
    }
});