如何从数组中删除一个特定值? 类似 :

array.remove(value);

制约:我必须使用核心 JavaScript 。 框架不允许 。


当前回答

let removeAnElement = (arr, element)=>{
    let findIndex = -1;
    for (let i = 0; i<(arr.length); i++){
        if(arr[i] === element){
            findIndex = i;
            break;
        }
    }
    if(findIndex == -1){
        return arr;
    }
    for (let i = findIndex; i<(arr.length-1); i++){
        arr[i] =  arr[i+1];
    }
    arr.length -= 1;
    return arr;
}

let array = ['apple', 'ball', 'cat', 'dog', 'egg'];
let removeElement = 'ball';

let tempArr2 = removeAnElement(array, 'dummy');
console.log(tempArr2);
// ['apple', 'cat', 'dog', 'egg']

let tempArr = removeAnElement(array, removeElement);
console.log(tempArr);`enter code here`
// ['apple', 'cat', 'dog', 'egg']

其他回答

通过我的解决方案, 您可以在纯 JavaScript 的阵列中删除一个或多个项。 不需要另外的 JavaScript 库 。

var myArray = [1,2,3,4,5]; // First array

var removeItem = function(array,value) {  // My clear function
    if(Array.isArray(value)) {  // For multi remove
        for(var i = array.length - 1; i >= 0; i--) {
            for(var j = value.length - 1; j >= 0; j--) {
                if(array[i] === value[j]) {
                    array.splice(i, 1);
                };
            }
        }
    }
    else { // For single remove
        for(var i = array.length - 1; i >= 0; i--) {
            if(array[i] === value) {
                array.splice(i, 1);
            }
        }
    }
}

removeItem(myArray,[1,4]); // myArray will be [2,3,5]

使用 JavaScript 原型特性定义列对象上名为删除() 的方法 。

使用 spolice () 方法满足您的要求 。

请看看下面的代码

Array.prototype.remove = function(item) {
    // 'index' will have -1 if 'item' does not exist,
    // else it will have the index of the first item found in the array
    var index = this.indexOf(item);

    if (index > -1) {
        // The splice() method is used to add/remove items(s) in the array
        this.splice(index, 1);
    }
    return index;
}

var arr = [ 11, 22, 67, 45, 61, 89, 34, 12, 7, 8, 3, -1, -4];

// Printing array
// [ 11, 22, 67, 45, 61, 89, 34, 12, 7, 8, 3, -1, -4];
console.log(arr)

// Removing 67 (getting its index, i.e. 2)
console.log("Removing 67")
var index = arr.remove(67)

if (index > 0){
    console.log("Item 67 found at ", index)
} else {
    console.log("Item 67 does not exist in array")
}

// Printing updated array
// [ 11, 22, 45, 61, 89, 34, 12, 7, 8, 3, -1, -4];
console.log(arr)

// ............... Output ................................
// [ 11, 22, 67, 45, 61, 89, 34, 12, 7, 8, 3, -1, -4 ]
// Removing 67
// Item 67 found at  2
// [ 11, 22, 45, 61, 89, 34, 12, 7, 8, 3, -1, -4 ]

注:以下是Norde.js REPL上执行的完整示例代码,该代码描述推()、流行()、转移()、非轮档()和交点()方法的使用。

> // Defining an array
undefined
> var arr = [12, 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34];
undefined
> // Getting length of array
undefined
> arr.length;
16
> // Adding 1 more item at the end i.e. pushing an item
undefined
> arr.push(55);
17
> arr
[ 12, 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34, 55 ]
> // Popping item from array (i.e. from end)
undefined
> arr.pop()
55
> arr
[ 12, 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
> // Remove item from beginning
undefined
> arr.shift()
12
> arr
[ 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
> // Add item(s) at beginning
undefined
> arr.unshift(67); // Add 67 at beginning of the array and return number of items in updated/new array
16
> arr
[ 67, 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
> arr.unshift(11, 22); // Adding 2 more items at the beginning of array
18
> arr
[ 11, 22, 67, 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
>
> // Define a method on array (temporarily) to remove an item and return the index of removed item; if it is found else return -1
undefined
> Array.prototype.remove = function(item) {
... var index = this.indexOf(item);
... if (index > -1) {
..... this.splice(index, 1); // splice() method is used to add/remove items in array
..... }
... return index;
... }
[Function]
>
> arr
[ 11, 22, 67, 45, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
>
> arr.remove(45);    // Remove 45 (you will get the index of removed item)
3
> arr
[ 11, 22, 67, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
>
> arr.remove(22)    // Remove 22
1
> arr
[ 11, 67, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
> arr.remove(67)    // Remove 67
1
> arr
[ 11, 67, 89, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
>
> arr.remove(89)    // Remove 89
2
> arr
[ 11, 67, 34, 12, 7, 8, 3, -1, -4, -11, 0, 56, 12, 34 ]
>
> arr.remove(100);  // 100 doesn't exist, remove() will return -1
-1
>

虽然大多数先前的答复都回答了这个问题,但是为什么没有使用切片()方法还不够清楚。 是的,过滤器()符合不可改变的标准,但做以下更短的等值如何?

const myArray = [1,2,3,4];

现在让我们说我们应该从阵列中删除第二个元素, 我们可以简单地做到:

const newArray = myArray.slice(0, 1).concat(myArray.slice(2, 4));

// [1,3,4]

今天,社区强烈鼓励从阵列中删除元素,因为其简单和不可改变的性质。 一般来说, 导致突变的方法应该避免。 例如, 鼓励您将推( ) 替换为 concat () , 并用切片 () 替换为 plus () 。

除了所有这些解决方案之外, 它也可以用阵列来完成. 减量...

const removeItem = 
    idx => 
    arr => 
    arr.reduce((acc, a, i) =>  idx === i ? acc : acc.concat(a), [])

const array = [1, 2, 3]
const index = 1

const newArray = removeItem(index)(array) 

console.log(newArray) // logs the following array to the console : [1, 3]

...或者一个循环函数(诚实地说不是那么优雅...也许有人有更好的循环解决方案? ? )...

const removeItemPrep = 
    acc => 
    i => 
    idx => 
    arr => 

    // If the index equals i, just feed in the unchanged accumulator(acc) else...
    i === idx ? removeItemPrep(acc)(i + 1)(idx)(arr) :

    // If the array length + 1 of the accumulator is smaller than the array length of the original array concatenate the array element at index i else... 
    acc.length + 1 < arr.length ? removeItemPrep(acc.concat(arr[i]))(i + 1)(idx)(arr) : 

    // return the accumulator
    acc 

const removeItem = removeItemPrep([])(0)

const array = [1, 2, 3]
const index = 1

const newArray = removeItem(index)(array) 

console.log(newArray) // logs the following array to the console : [1, 3]

更现代的ECMAScript 2015(原称和谐或ES6)方法。

const items = [1, 2, 3, 4];
const index = 2;

然后:

items.filter((x, i) => i !== index);

弹出 :

[1, 2, 4]

您可以使用 Babel 和多填充服务,以确保浏览器之间有很好的支持。