ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
89 lines
1.9 KiB
Markdown
89 lines
1.9 KiB
Markdown
---
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id: 56bbb991ad1ed5201cd392cc
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title: 使用 pop() 操作数组
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cRbVZAB'
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forumTopicId: 18236
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dashedName: manipulate-arrays-with-pop
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---
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# --description--
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改变数组中数据的另一种方法是用`.pop()`函数。
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`.pop()`函数用来“抛出”一个数组末尾的值。我们可以把这个“抛出”的值赋给一个变量存储起来。换句话说就是`.pop()`函数移除数组末尾的元素并返回这个元素。
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数组中任何类型的元素（数值，字符串，甚至是数组）可以被“抛出来” 。
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```js
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var threeArr = [1, 4, 6];
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var oneDown = threeArr.pop();
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console.log(oneDown); // Returns 6
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console.log(threeArr); // Returns [1, 4]
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```
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# --instructions--
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使用`.pop()`函数移除`myArray`中的最后一个元素，并且把“抛出”的值赋给`removedFromMyArray`。
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# --hints--
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`myArray`应该只包含`[["John", 23]]`。
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```js
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assert(
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(function (d) {
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if (d[0][0] == 'John' && d[0][1] === 23 && d[1] == undefined) {
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return true;
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} else {
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return false;
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}
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})(myArray)
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);
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```
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对`myArray`使用`pop()`函数。
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```js
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assert(/removedFromMyArray\s*=\s*myArray\s*.\s*pop\s*(\s*)/.test(code));
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```
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`removedFromMyArray`应该只包含`["cat", 2]`。
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```js
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assert(
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(function (d) {
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if (d[0] == 'cat' && d[1] === 2 && d[2] == undefined) {
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return true;
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} else {
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return false;
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}
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})(removedFromMyArray)
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);
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```
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# --seed--
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## --after-user-code--
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```js
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(function(y, z){return 'myArray = ' + JSON.stringify(y) + ' & removedFromMyArray = ' + JSON.stringify(z);})(myArray, removedFromMyArray);
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```
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## --seed-contents--
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```js
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// Setup
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var myArray = [["John", 23], ["cat", 2]];
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// Only change code below this line
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var removedFromMyArray;
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```
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# --solutions--
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```js
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var myArray = [["John", 23], ["cat", 2]];
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var removedFromMyArray = myArray.pop();
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```
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