20 lines
1.0 KiB
Markdown
20 lines
1.0 KiB
Markdown
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---
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title: Copy an Array with the Spread Operator
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localeTitle: 使用Spread Operator复制数组
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---
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## 使用Spread Operator复制数组
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* 示例中的最后一个提示告诉您使用最近学习的方法。
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* spread运算符将所有元素复制到一个新的空对象中。
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\`\`\`的JavaScript while（num> = 1）{ newArr = \[... arr\] num--; }
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```
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- The code above will copy all of the elements into `newArr` but will also reinitialise `newArr` with every new iteration of the while loop.
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- 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.
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## Solution:
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```
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JavaScript的 function copyMachine（arr，num）{ 让newArr = \[\]; while（num> = 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; }
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//在此处更改代码以测试不同的情况： console.log（copyMachine（\[true，false，true\]，2））; \`\`\`
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