在JavaScript函数之后保留原始数组 [英] Keep original array after JavaScript function

问题描述

尽管我只有PHP的实际经验，但我肯定对此有一个简单的答案.为什么将"pizza"数组传递给函数"my_pizza"而仅对"my_pizza"进行更改，为什么会更改?如何将传递给函数的原始数组保留在函数之外?函数完成运行后，披萨数组应该没有更改.我注意到，如果更改字符串变量(pie)，它将在函数运行后保持不变，这与数组不同.

I'm sure there is an easy answer for this, though I only really have experience with PHP. Why does the "pizza" array change when I pass it to my function as "my_pizza" and only make changes to "my_pizza"? How do I keep my original array I pass to the function outside of the function? Once the function is finished running, the pizza array should have not changed. I noticed if I change my string variable (pie) it will stay the same after the function runs, unlike the array.

简而言之，我希望第一组结果与第二组相同.

In short, I want the first set of results to be identical to the second.

var pizza = [];
pizza.push('crust');
pizza.push('ham');

var pie = "apple"

function bake_goods(my_pizza, my_pie){
    console.log(my_pizza);
    console.log(my_pie);

    delete my_pizza['1'];
    my_pie = "peach";

    console.log(my_pizza);
    console.log(my_pie);
}

//first run

bake_goods(pizza, pie);
//console logs
//['crust','ham']
//apple

//['crust']
//peach

//second run

bake_goods(pizza, pie);
//console logs
//['crust']
//apple

//['crust']
//peach

推荐答案

您应该在函数中克隆(创建副本)

you should clone (create a copy of) your array in your function

function bake_goods(my_pizza, my_pie){
    var innerPizza = my_pizza.slice(0);
    console.log(innerPizza);
    console.log(my_pie);

    delete innerPizza ['1'];
    my_pie = "peach";

    console.log(innerPizza );
    console.log(my_pie);
}

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