我有var ar = [1, 2, 3, 4, 5]并想要一些函数getSubarray(array, fromIndex, toIndex)，调用的结果getSubarray(ar, 1, 3)是新数组[2, 3, 4]。
如何从数组中获取子数组？
IT技术
javascript
arrays
2021-01-23 13:56:01
4个回答
const ar = [1, 2, 3, 4, 5];
// slice from 1..3 - add 1 as the end index is not included
const ar2 = ar.slice(1, 3 + 1);
console.log(ar2);对于 的简单使用slice，请使用我对 Array Class 的扩展：
Array.prototype.subarray = function(start, end) {
if (!end) { end = -1; }
return this.slice(start, this.length + 1 - (end * -1));
};
然后：
var bigArr = ["a", "b", "c", "fd", "ze"];
测试1：
bigArr.subarray(1, -1);
< ["b", "c", "fd", "ze"]
测试2：
bigArr.subarray(2, -2);
< ["c", "fd"]
测试3：
bigArr.subarray(2);
< ["c", "fd","ze"]
对于来自另一种语言（即 Groovy）的开发人员来说可能更容易。
const array_one = [11, 22, 33, 44, 55];
const start = 1;
const end = array_one.length - 1;
const array_2 = array_one.slice(start, end);
console.log(array_2);该问题是实实在在的一个新的数组，所以我认为一个更好的解决办法是结合Abdennour•图米的答案与克隆功能：
function clone(obj) {
if (null == obj || "object" != typeof obj) return obj;
const copy = obj.constructor();
for (const attr in obj) {
if (obj.hasOwnProperty(attr)) copy[attr] = obj[attr];
}
return copy;
}
// With the `clone()` function, you can now do the following:
Array.prototype.subarray = function(start, end) {
if (!end) {
end = this.length;
}
const newArray = clone(this);
return newArray.slice(start, end);
};
// Without a copy you will lose your original array.
// **Example:**
const array = [1, 2, 3, 4, 5];
console.log(array.subarray(2)); // print the subarray [3, 4, 5, subarray: function]
console.log(array); // print the original array [1, 2, 3, 4, 5, subarray: function][ http://stackoverflow.com/questions/728360/most-elegant-way-to-clone-a-javascript-object]
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