JavaScript syntax is the set of rules, how JavaScript programs are constructed:
// How to create variables:
var x;
let y;
// How to use variables:
x = 5;
y = 6;
let z = x + y;
JavaScript Values
The JavaScript syntax defines two types of values:
- Fixed values
- Variable values
Fixed values are called Literals.
Variable values are called Variables.
JavaScript Literals
The two most important syntax rules for fixed values are:
1. Numbers are written with or without decimals:
10.50
1001
2. Strings are text, written within double or single quotes:
"John Doe"
'John Doe'
JavaScript Variables
In a programming language, variables are used to store data values.
JavaScript uses the keywords var,
let and const to declare variables.
An equal sign is used to assign values to variables.
In this example, x is defined as a variable. Then, x is assigned (given) the value 6:
let x;
x = 6;