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>
119 lines
3.4 KiB
Markdown
119 lines
3.4 KiB
Markdown
---
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id: 587d7b8a367417b2b2512b4e
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title: Create Strings using Template Literals
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challengeType: 1
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forumTopicId: 301200
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dashedName: create-strings-using-template-literals
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---
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# --description--
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A new feature of ES6 is the <dfn>template literal</dfn>. This is a special type of string that makes creating complex strings easier.
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Template literals allow you to create multi-line strings and to use string interpolation features to create strings.
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Consider the code below:
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```js
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const person = {
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name: "Zodiac Hasbro",
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age: 56
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};
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// Template literal with multi-line and string interpolation
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const greeting = `Hello, my name is ${person.name}!
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I am ${person.age} years old.`;
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console.log(greeting); // prints
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// Hello, my name is Zodiac Hasbro!
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// I am 56 years old.
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```
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A lot of things happened there. Firstly, the example uses backticks (`` ` ``), not quotes (`'` or `"`), to wrap the string. Secondly, notice that the string is multi-line, both in the code and the output. This saves inserting `\n` within strings. The `${variable}` syntax used above is a placeholder. Basically, you won't have to use concatenation with the `+` operator anymore. To add variables to strings, you just drop the variable in a template string and wrap it with `${` and `}`. Similarly, you can include other expressions in your string literal, for example `${a + b}`. This new way of creating strings gives you more flexibility to create robust strings.
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# --instructions--
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Use template literal syntax with backticks to create an array of list element (`li`) strings. Each list element's text should be one of the array elements from the `failure` property on the `result` object and have a `class` attribute with the value `text-warning`. The `makeList` function should return the array of list item strings.
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Use an iterator method (any kind of loop) to get the desired output (shown below).
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```js
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[
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'<li class="text-warning">no-var</li>',
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'<li class="text-warning">var-on-top</li>',
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'<li class="text-warning">linebreak</li>'
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]
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```
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# --hints--
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`failuresList` should be an array containing `result failure` messages.
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```js
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assert(
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typeof makeList(result.failure) === 'object' && failuresList.length === 3
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);
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```
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`failuresList` should be equal to the specified output.
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```js
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assert(
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makeList(result.failure).every(
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(v, i) =>
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v === `<li class="text-warning">${result.failure[i]}</li>` ||
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v === `<li class='text-warning'>${result.failure[i]}</li>`
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)
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);
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```
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Template strings and expression interpolation should be used.
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```js
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(getUserInput) => assert(getUserInput('index').match(/(`.*\${.*}.*`)/));
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```
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An iterator should be used.
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```js
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(getUserInput) =>
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assert(getUserInput('index').match(/for|map|reduce|forEach|while/));
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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 result = {
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success: ["max-length", "no-amd", "prefer-arrow-functions"],
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failure: ["no-var", "var-on-top", "linebreak"],
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skipped: ["no-extra-semi", "no-dup-keys"]
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};
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function makeList(arr) {
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// Only change code below this line
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const failureItems = [];
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// Only change code above this line
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return failureItems;
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}
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const failuresList = makeList(result.failure);
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```
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# --solutions--
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```js
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const result = {
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success: ["max-length", "no-amd", "prefer-arrow-functions"],
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failure: ["no-var", "var-on-top", "linebreak"],
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skipped: ["no-extra-semi", "no-dup-keys"]
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};
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function makeList(arr) {
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return arr.map(val => `<li class="text-warning">${val}</li>`);
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}
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const failuresList = makeList(result.failure);
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```
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