Quick Reference
The var statement declares a variable (container for storing information), and can be empty when declared, with the value assigned later.
// variable without a defined value; will return "undefined"
var my_greeting;// empty variable; will return nothing (but is defined)
var my_greeting = '';// variable with assigned value
var my_greeting = 'Hello World';Note
After the initial declaration of the variable, when changing the value or removing the value, there is no need to use “var” again.
// changing the assigned value at a later point
my_greeting = 'Hello World';// removing the assigned value at a later point
my_greeting = '';Syntax
var name;var name = '';var name = 'var_name';JavaScript Notes:
- When using JavaScript, single or double quotation marks are acceptable and work identically to one another; choose whichever you prefer, and stay consistent
- JavaScript is a case-sensitive language; firstName is NOT the same as firstname
- Arrays count starting from zero NOT one; so item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on
- JavaScript variables must begin with a letter, $, or _
- JavaScript variables are case sensitive (x is not the same as X)
We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.