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>
99 lines
2.2 KiB
Markdown
99 lines
2.2 KiB
Markdown
---
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id: 587d7b89367417b2b2512b49
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title: Use Destructuring Assignment to Assign Variables from Objects
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challengeType: 1
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forumTopicId: 301215
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dashedName: use-destructuring-assignment-to-assign-variables-from-objects
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---
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# --description--
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Destructuring allows you to assign a new variable name when extracting values. You can do this by putting the new name after a colon when assigning the value.
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Using the same object from the last example:
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```js
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const user = { name: 'John Doe', age: 34 };
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```
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Here's how you can give new variable names in the assignment:
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```js
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const { name: userName, age: userAge } = user;
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// userName = 'John Doe', userAge = 34
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```
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You may read it as "get the value of `user.name` and assign it to a new variable named `userName`" and so on.
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# --instructions--
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Replace the two assignments with an equivalent destructuring assignment. It should still assign the variables `highToday` and `highTomorrow` the values of `today` and `tomorrow` from the `HIGH_TEMPERATURES` object.
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# --hints--
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You should remove the ES5 assignment syntax.
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```js
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assert(
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!code.match(/highToday = HIGH_TEMPERATURES\.today/g) &&
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!code.match(/highTomorrow = HIGH_TEMPERATURES\.tomorrow/g)
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);
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```
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You should use destructuring to create the `highToday` variable.
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```js
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assert(
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code.match(
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/(var|const|let)\s*{\s*(today\s*:\s*highToday[^}]*|[^,]*,\s*today\s*:\s*highToday\s*)}\s*=\s*HIGH_TEMPERATURES(;|\s+|\/\/)/g
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)
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);
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```
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You should use destructuring to create the `highTomorrow` variable.
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```js
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assert(
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code.match(
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/(var|const|let)\s*{\s*(tomorrow\s*:\s*highTomorrow[^}]*|[^,]*,\s*tomorrow\s*:\s*highTomorrow\s*)}\s*=\s*HIGH_TEMPERATURES(;|\s+|\/\/)/g
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)
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);
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```
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`highToday` should be equal to `77` and `highTomorrow` should be equal to `80`.
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```js
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assert(highToday === 77 && highTomorrow === 80);
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```
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# --seed--
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## --seed-contents--
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```js
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const HIGH_TEMPERATURES = {
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yesterday: 75,
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today: 77,
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tomorrow: 80
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};
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// Only change code below this line
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const highToday = HIGH_TEMPERATURES.today;
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const highTomorrow = HIGH_TEMPERATURES.tomorrow;
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// Only change code above this line
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```
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# --solutions--
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```js
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const HIGH_TEMPERATURES = {
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yesterday: 75,
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today: 77,
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tomorrow: 80
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};
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const { today: highToday, tomorrow: highTomorrow } = HIGH_TEMPERATURES;
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```
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