如何从数组中删除一个特定值? 类似 :
array.remove(value);
我必须使用核心核心核心JavaScript。 不允许框架 。
如何从数组中删除一个特定值? 类似 :
array.remove(value);
我必须使用核心核心核心JavaScript。 不允许框架 。
当前回答
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]
其他回答
使用.indexof () 和.spolice () - 可变模式
这里有两种情况:
const drinks = [ 'Tea', 'Coffee', 'Milk'];
const id = 1;
const removedDrink = drinks.splice(id, 1);
console.log(removedDrink)
const drinks = ['Tea','Coffee', 'Milk'];
const id = drinks.indexOf('Coffee'); // 1
const removedDrink = drinks.splice(id, 1);
// ["Coffee"]
console.log(removedDrink);
// ["Tea", "Milk"]
console.log(drinks);
使用. filter () - 不可变模式
你可以想到的最好方式是 — — 而不是“删除”该项目,而是“创造”一个新的阵列,只是不包含该项目。 所以我们必须找到它,完全省略它。
const drinks = ['Tea','Coffee', 'Milk'];
const id = 'Coffee';
const idx = drinks.indexOf(id);
const removedDrink = drinks[idx];
const filteredDrinks = drinks.filter((drink, index) => drink == removedDrink);
console.log("Filtered Drinks Array:"+ filteredDrinks);
console.log("Original Drinks Array:"+ drinks);
2017-05-08
大多数给定的回答都用于严格的比较, 意思是两个对象在内存( 或原始类型) 中引用完全相同的对象, 但通常您想要从具有一定值的数组中删除一个非原始对象。 例如, 如果您给服务器打电话, 并想要对照本地对象检查已检索到的对象 。
const a = {'field': 2} // Non-primitive object
const b = {'field': 2} // Non-primitive object with same value
const c = a // Non-primitive object that reference the same object as "a"
assert(a !== b) // Don't reference the same item, but have same value
assert(a === c) // Do reference the same item, and have same value (naturally)
//Note: there are many alternative implementations for valuesAreEqual
function valuesAreEqual (x, y) {
return JSON.stringify(x) === JSON.stringify(y)
}
//filter will delete false values
//Thus, we want to return "false" if the item
// we want to delete is equal to the item in the array
function removeFromArray(arr, toDelete){
return arr.filter(target => {return !valuesAreEqual(toDelete, target)})
}
const exampleArray = [a, b, b, c, a, {'field': 2}, {'field': 90}];
const resultArray = removeFromArray(exampleArray, a);
//resultArray = [{'field':90}]
数值AreEqual有替代/更快的操作,但这样可以操作。如果您有特定的字段要检查,也可以使用自定义的比较器(例如,有些已检索的 UUID 相对于本地的 UUID ) 。
2. 还注意到这是一个功能操作,意即它不改变原始阵列。
(function removeFromArrayPolyfill() {
if (window.Array.prototype.remove) return;
Array.prototype.remove = function (value) {
if (!this.length || !value) return;
const indexOfValue = this.indexOf(value);
if (indexOfValue >= 0) {
this.splice(indexOfValue, 1);
}
};
})();
// testing polyfill
const nums = [10, 20, 30];
nums.remove(20);
console.log(nums);//[10,30]
您可以用所有存取器示例创建索引 :
<div >
</div>
function getIndex($id){
return (
this.removeIndex($id)
alert("This element was removed")
)
}
function removeIndex(){
const index = $id;
this.accesor.id.splice(index.id) // You can use splice for slice index on
// accessor id and return with message
}
<div>
<fromList>
<ul>
{...this.array.map( accesors => {
<li type="hidden"></li>
<li>{...accesors}</li>
})
}
</ul>
</fromList>
<form id="form" method="post">
<input id="{this.accesors.id}">
<input type="submit" callbackforApplySend...getIndex({this.accesors.id}) name="sendendform" value="removeIndex" >
</form>
</div>
Array.prototype.removeItem = function(a) {
for (i = 0; i < this.length; i++) {
if (this[i] == a) {
for (i2 = i; i2 < this.length - 1; i2++) {
this[i2] = this[i2 + 1];
}
this.length = this.length - 1
return;
}
}
}
var recentMovies = ['Iron Man', 'Batman', 'Superman', 'Spiderman'];
recentMovies.removeItem('Superman');