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>
61 lines
2.0 KiB
Markdown
61 lines
2.0 KiB
Markdown
---
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id: bd7123c9c443eddfaeb5bdef
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title: Declare JavaScript Variables
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cNanrHq'
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forumTopicId: 17556
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dashedName: declare-javascript-variables
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---
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# --description--
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In computer science, <dfn>data</dfn> is anything that is meaningful to the computer. JavaScript provides eight different <dfn>data types</dfn> which are `undefined`, `null`, `boolean`, `string`, `symbol`, `bigint`, `number`, and `object`.
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For example, computers distinguish between numbers, such as the number `12`, and `strings`, such as `"12"`, `"dog"`, or `"123 cats"`, which are collections of characters. Computers can perform mathematical operations on a number, but not on a string.
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<dfn>Variables</dfn> allow computers to store and manipulate data in a dynamic fashion. They do this by using a "label" to point to the data rather than using the data itself. Any of the eight data types may be stored in a variable.
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`Variables` are similar to the x and y variables you use in mathematics, which means they're a simple name to represent the data we want to refer to. Computer `variables` differ from mathematical variables in that they can store different values at different times.
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We tell JavaScript to create or <dfn>declare</dfn> a variable by putting the keyword `var` in front of it, like so:
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```js
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var ourName;
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```
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creates a `variable` called `ourName`. In JavaScript we end statements with semicolons. `Variable` names can be made up of numbers, letters, and `$` or `_`, but may not contain spaces or start with a number.
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# --instructions--
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Use the `var` keyword to create a variable called `myName`.
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**Hint**
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Look at the `ourName` example above if you get stuck.
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# --hints--
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You should declare `myName` with the `var` keyword, ending with a semicolon
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```js
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assert(/var\s+myName\s*;/.test(code));
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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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if(typeof myName !== "undefined"){(function(v){return v;})(myName);}
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```
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## --seed-contents--
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```js
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```
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# --solutions--
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```js
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var myName;
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```
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