JavaScript Syntax

Just like all programming language,in JavaScript also, the Syntax defines how to construct the language. It is the principle by which the language is constructed. The sentences of a programming language is called statements.

JavaScript Character Set

JavaScript uses Unicode character set. Unicode cover almost all characters, punctuations, and symbols in the world. Unicode enables processing, storage, and transport of text, independent of platform and language. Unicode can be implemented by different character set. The most commonly used encoding are UTF-8 and UTF-16. A character set contains the following:

1. Letters: The English alphabets (A to Z and a to z)
2. Digits: The Numerals (0 to 9)
3. Special Characters: + - * / \ ! @ # $ % ^ & * ( ) _ - = [ ] { } | ; : " ' , . ? etc
4. White spaces: Blank Space (Space bar), Tab, Return etc
5. Other characters: Non-Graphic Symbols.

JavaScript Functions

A function is a block of code designed to perform a particular task. JavaScript statements written inside a JavaScript function, can be invoked many times as the user desires. To invoke a function means to call upon the function or asking up the code in the function which is being called to be executed.

For example:

function myFunction (a, b) {
 return a + b;
}

JavaScript Data Type

JavaScript data types are the data's provided to an variable. It can be anything like number, characters, text string, arrays, objects, and much more. A programming language like JavaScript has to deal with all kinds of data. Data types are defined to differentiate the nature and size of incoming data. JavaScript is flexible enough to allow user to define data types therefore increasing its demand in the programming world.

For example:

var number = 10;
var name = "Edwin";
var language = ["HTML","CSS","JavaScript","jQuery"]

JavaScript Keywords

A JavaScript statement always starts with a keyword. The words that convey a specific meaning to the language compilers are called keywords. These are also known as reserved words as they are reserved by the language for special purpose and cannot be redefined for any other purpose.

abstract	else	instanceof	super
boolean	enum	int	switch
break	export	interface	synchronized
byte	extends	let	this
case	false	long	throw
catch	final	native	throws
char	finally	new	transient
class	float	null	true
const	for	package	try
continue	function	private	typeof
debugger	goto	protected	var
default	if	public	void
delete	implements	return	volatile
do	import	short	while
double	in	static	with

For example:

var x = 5 + 6;
var y = a * b;

JavaScript Identifiers

All programming languages must identify variables, functions, and objects with unique name. These unique names are called identifiers. Identifiers are the user defines words that are used to name different program elements such as memory locations, functions, statements, objects, classes etc. These are the fundamental building blocks of the program. The identifiers of memory locations are called variables; of functions are called function names; of statements are called labels and so on.

JavaScript Literals

Literals are tokens that represent data items that never change their value during the program run. They are often referred to as constants. In programming language, literals are constants. Number literals can be written with or without decimal points, and wit or without scientific notations. String literals can be written with double or single quotes.

For example:

3.14
1001
123e5
"Edwin Ronald Lambert"
'Edwin Ronald Lambert'

JavaScript Operators

Data processing is a sequence of operations. Operators are predefined symbols that can carry out operations. Operators are the token that triggers some kind of operations on the data. The data on which the operations are carried out are called operands. The operands may be either a constant or a variable. Generally operators perform the operations and return some results.

For example:

x = 5;
y = 6;
z = x + y;

JavaScript Statements

JavaScript statements are commands to the browser. It tells the browser what function it has to do. JavaScript ignores spaces, tabs and newlines that appears in a JavaScript program. Because of that, it allows you to format and indent the program in a neat and consistent way that make the code easy to read and understand. Semicolon separates the JavaScript statements. Therefore we add semicolon at the end of each executable statements.

For example:

x = 5 + 6;
y = x * 10;

JavaScript Variables

In JavaScript, variables are the named memory locations capable of storing constants or data. in fact, variables are containers for storing informations or data. A variable can be defined in any data type. The size and nature of data stored in a variable depends on the data type , it is declared. The equal sign assigns a value to a named variable.

For example:

x = 5;
y = 6;
z = x + y;

JavaScript Comments

JavaScript comments are used to explain the code and make the code more readable. It can also be used to prevent execution during testing alternative codes.

For example:

//This is a single line comment. I will not be executed.

/*
This is a double line comment.
I will not be executed.
*/