freeCodeCamp/guide/chinese/certifications/javascript-algorithms-and-d.../basic-data-structures/copy-an-array-with-the-spre.../index.md

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Copy an Array with the Spread Operator 使用Spread Operator复制数组

使用Spread Operator复制数组

  • 示例中的最后一个提示告诉您使用最近学习的方法。
  • spread运算符将所有元素复制到一个新的空对象中。

```的JavaScript whilenum> = 1{ newArr = [... arr] num--; }

- The code above will copy all of the elements into `newArr` but will also reinitialise `newArr` with every new iteration of the while loop. 
 - A new variable should first be initialised using the spread operator - `let obj = [...arr];` - then this variable should be added to the `newArr` for every iteration of the while loop. 
 
 ## Solution: 

JavaScript的 function copyMachinearrnum{ 让newArr = []; whilenum> = 1{ //更改此行下方的代码 newArr.push[... ARR]; //更改此行以上的代码 num--; } 返回newArr; }

//在此处更改代码以测试不同的情况: console.logcopyMachine[truefalsetrue]2; ```