* fix: remove isHidden flag from frontmatter * fix: add isUpcomingChange Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com> * feat: hide blocks not challenges Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com> Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com>
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id, title, challengeType, videoUrl, forumTopicId
id | title | challengeType | videoUrl | forumTopicId |
---|---|---|---|---|
bd7123c9c443eddfaeb5bdef | Declare JavaScript Variables | 1 | https://scrimba.com/c/cNanrHq | 17556 |
Description
undefined
, null
, boolean
, string
, symbol
, bigint
, number
, and object
.
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.
Variables 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.
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.
We tell JavaScript to create or declare a variable by putting the keyword var
in front of it, like so:
var ourName;
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.
Instructions
var
keyword to create a variable called myName
.
HintLook at the
ourName
example above if you get stuck.
Tests
tests:
- text: You should declare <code>myName</code> with the <code>var</code> keyword, ending with a semicolon
testString: assert(/var\s+myName\s*;/.test(code));
Challenge Seed
After Test
if(typeof myName !== "undefined"){(function(v){return v;})(myName);}
Solution
var myName;