Semicolons ;

Semicolons separate JavaScript statements.

Add a semicolon at the end of each executable statement:

var a, b, c;     // Declare 3 variables

a = 5;           // Assign the value 5 to a

b = 6;           // Assign the value 6 to b

c = a + b;       // Assign the sum of a and b to c

When separated by semicolons, multiple statements on one line are allowed:

a = 5; b = 6; c = a + b;

On the web, you might see examples without semicolons.

Ending statements with semicolon is not required, but highly recommended.

JavaScript White Space

JavaScript ignores multiple spaces. You can add white space to your script to make it more readable.

The following lines are equivalent:

var person = "Hege";

var person="Hege";

A good practice is to put spaces around operators ( = + - * / ):

var x = y + z;

JavaScript Line Length and Line Breaks

For best readability, programmers often like to avoid code lines longer than 80 characters.

If a JavaScript statement does not fit on one line, the best place to break it is after an operator:

Example

document.getElementById("demo").innerHTML =

"Hello Dolly!";

JavaScript Code Blocks

JavaScript statements can be grouped together in code blocks, inside curly brackets {...}.

The purpose of code blocks is to define statements to be executed together.

One place you will find statements grouped together in blocks, is in JavaScript functions:

Example

function myFunction() {

  document.getElementById("demo1").innerHTML = "Hello Dolly!";

  document.getElementById("demo2").innerHTML = "How are you?";

}

In this tutorial we use 2 spaces of indentation for code blocks.

You will learn more about functions later in this tutorial.