方法Array.splice VS设定值设置为null [英] array.splice vs setting a value to null

问题描述

您应该使用方法Array.splice（I，1）; 而不是数组[我] = NULL 此将preserve阵列中的键

You should use array.splice(i, 1); instead of array[i] = null This will preserve the keys in the array

来源：我应该懒得清洗阵中的node.js <？ / A>

Source : Should I bother cleaning array in node.js?

我真的不理解这句话。为什么数组[我] = NULL 将改变阵的钥匙？为什么方法Array.splice（1,1）; 更好

I don't really understand this sentence. Why array[i] = null will change the keys of the array ? Why array.splice(i, 1); is better ?

推荐答案

方法Array.splice（I，1）; 从数组中删除的元素，所以改变了长度阵。

array.splice(i, 1); will remove the element from array, so changing the length of array.

而数组[我] = NULL 将只指数 I 的值设置为无效并不会改变数组的长度。这是一样的删除阵列[我] 除了删除运营商将在索引处的值设置为未定义。

Whereas array[i] = null will just set the value at the index i to null and will not alter the array length. This is same as delete array[i] except the delete operator will set the value at the index to undefined.

关于

为什么数组[我] = NULL 将改变阵的钥匙？

Why array[i] = null will change the keys of the array?

我觉得在意志和变化之间缺少一个字的不的

I think there is missing a word not in between the will and change.

因此​​，根据对我来说，它应该是

So, according to me, it should be

为什么数组[我] = NULL 将不可以更改密钥（或相当的长度的）的数组？

Why array[i] = null will not change the keys(or rather length) of the array?

第二个问题：

为什么方法Array.splice（1,1）; 更好

这从它删除元素改变了数组的长度。所以，遍历数组时，你不必检查如果（价值== NULL）。

It alters the length of the array by removing the element from it. So, when iterating over array you don't have to check if(value == null).

要完全使用哪一个取决于所使用的情况。

Which one to use totally depends on the use-case.

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