[TIL] 20201125 JavaScript Basics

Primitive Types

• Number
• String
• Boolean
• Null
• Undefined
• Symbol
• BigInt

 

 

JavaScript Numbers

• JavaScript has ONE number type
• Math operations
  • add : +
  • subtraction : -
  • multiplication : *
  • division : /
  • modulo(remainder operator) : %
  • exponentiation : **

 

 

NaN

• "Not a Number"
• NaN is a numeric value that represents something that is not a number.
• ex) 0/0, 1+NaN

 

 

Variables

• Labels for values
• Basic Syntax
  • let x = value;
  • ex) let year = 1956;

 

 

Updating Variables

• +=, -=, *=, /= operations

//EXAMPLES
//These two operations are exactly the same.

score = score+5;
score += 5;

• ++, -- operations
  • add/subtract 1

 

 

Const & Var

• const
  • stands for constant
  • The value can't be changed.
• var
  • The old variable keyword.
  • Before let&const, var was the only option. There isn't really a reason to use it now.

 

 

Booleans

• value: true, false

 

 

Variable Naming and Conventions

• Hard Rules for Naming
  • No space allowed within the name.
  • Can't start with number.
• Best Practices
  • Camel Cased : If there are more than one word for the name, start the first one with lowercase and others with uppercase.
  • Use recognizable names.

 

 

 

 

 

 

 

* This post is a summary of Udemy Course "The Web Developer Bootcamp" by Colt Steele.