在JavaScript中，有没有办法将数组的元素传递给函数而不传入整个数组？(In JavaScript, is there any way of passing elements of an arr

在JavaScript中，有没有办法将数组的元素传递给函数而不传入整个数组？(In JavaScript, is there any way of passing elements of an array into a function without passing in the entire array?)

例如，在

function swap ( arr, i1, i2 ) { // swaps elements at index i1 and i2 // in the array arr var temp = arr[i1]; arr[i1] = arr[i2]; arr[i2] = temp; } function reverse_array ( arr ) { // reverse the order of the elements in array arr var i1 = 0, i2 = arr.length; while ( i1 != i2 && i1 != --i2 ) swap(arr,i1++,i2); } var myArray = [1, 2, 3, 4]; reverse_array(myArray); myArray.forEach(function(elem) { $('#mydiv').append(elem + ' ') });

我知道为数组元素实现swap函数的唯一方法是传入数组。但是，这似乎效率低下。 必须有一种方法可以为任何类型的变量实现直接swap功能。 我想我的问题可以归结为：

在JavaScript中实现交换功能的最有效方法是什么？

在将变量传递给经典function swap ( a, b ) { temp = a; a = b; b = temp; }之前，有没有一种方法可以“装箱”（使用C＃术语）变量function swap ( a, b ) { temp = a; a = b; b = temp; } function swap ( a, b ) { temp = a; a = b; b = temp; } 程序？

For example, in

function swap ( arr, i1, i2 ) { // swaps elements at index i1 and i2 // in the array arr var temp = arr[i1]; arr[i1] = arr[i2]; arr[i2] = temp; } function reverse_array ( arr ) { // reverse the order of the elements in array arr var i1 = 0, i2 = arr.length; while ( i1 != i2 && i1 != --i2 ) swap(arr,i1++,i2); } var myArray = [1, 2, 3, 4]; reverse_array(myArray); myArray.forEach(function(elem) { $('#mydiv').append(elem + ' ') });

the only way I know of implementing a swap function for elements of an array is to pass in the array in. However, that seems inefficient. There must a way of implementing a straight-up swap function for variables of any type. I guess my question really boils down to:

What is the most efficient way of implementing a swap function in JavaScript???

Is there a way of "boxing" (to use a C# term) to variables before passing them into a classic function swap ( a, b ) { temp = a; a = b; b = temp; } procedure?

最满意答案

如果使用ECMAScript6，则可以使用解构来交换。

var a = 0; var b = 1; [a, b] = [b, a];

这非常方便，也是我喜欢Javascript的原因之一。

但在使用之前请检查兼容性。 否则你必须使用temp var。

您可以使用该方法反转数组。

var arr = [1,2,3,4,5,6,7]; arr.reverse(); // [7,6,5,4,3,2,1]

传递数组也不是低效的。 您所做的只是传递对数组的引用，并且比从数组传递两个元素更有效。

所有变量都通过引用在内部进行标识，当您将引用传递给函数时，数组或对象的大小对代码速度没有影响。

If you use ECMAScript6 you can use destructuring to swap.

var a = 0; var b = 1; [a, b] = [b, a];

Which is very handy and one of the reasons I love Javascript.

But check for compatability before you use it. Otherwise you have to use a temp var.

You can reverse an array with the method.

var arr = [1,2,3,4,5,6,7]; arr.reverse(); // [7,6,5,4,3,2,1]

Also passing an array is not inefficient. All you do is pass a reference to the array, and is more efficient than passing two elements from the array.

All variables are identified internally via a reference, the size of the array or object has no effect on code speed when you pass the reference to functions.