从 JavaScript 数组中删除特定索引

Question

我写了一些代码来跟踪我成功的索引，但发现很难将它们从数组中删除，所以我对剩下的做了同样的事情。

 var v = [4, 7, 2,5, 3] 
 var f = []
 for (let i = 1; i < v.length; i += 2){
/*(point1)this line doesn't seem to work*/
 if (v[i] > v[i] - 1)
/*(point 2) Instead of console.log I want to delete every of v[i] */
console.log(v[i])

输出

7
5

删除 v[I] 时的预期输出

 v = [4,2,3]

最好我想做一些类似 splice v[i] 如果 v[i] > v[i] -1 的事情，然后像拼接元素一样返回 v。

我首先在命令行中使用这种类似的逻辑测试了第 1 点，但它工作正常，但是.....;

   if ((b[1] -1) > b[0]){console.log(b[2])}

输出

3
```

Answer 1

要删除数组的特定索引，您可以使用如下拼接。

var fruits = ["apple", "orange", "avocado", "banana"];
//remove one element starting from index 2
var removed = fruits.splice(2, 1);
//fruits is ["apple", "orange", "banana"]
//removed is ["avocado"]

但是，关于 if 逻辑，它将始终为真，因为您正在测试一个数字是否大于其自身减去 1。如果您尝试测试当前数组位置中的值是否大于前一个位置中的值，所以你应该这样。

if (v[i] > v[i-1])

Answer 2

通过从数组v消除不需要的元素来构建新的数组res

 var v = [4, 7, 2, 5, 3]; var res = []; res.push(v[0]); for (let i = 1; i < v.length; i += 1) { if (v[i - 1] > v[i]) { res.push(v[i]); } } console.log(res);

Answer 3

尝试数组对象的filter 方法。

您可以使用数组对象的 filter 方法过滤掉所需的值并获取新数组，而不是从当前数组中删除元素。

 var arr = [0, 1, 2, 3]; var filteredArr = arr.filter(function(element, currentIndex, arrObj) { //currentIndex and arrObj can be used to form your desired condition but they are //optional parameter // below is the filter condition to be applied on each element return element > 0; }); console.log('filteredArr will have all the elements of the array which satisfies the filter condition:', filteredArr);