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JavaScript var Statement

❮ JavaScript Statements Reference

Example

Create a variable called carName and assign the value "Volvo" to it:

var carName = "Volvo";
Try it Yourself »

More "Try it Yourself" examples below.


Definition and Usage

The var statement declares a variable.

Variables are containers for storing information.

Creating a variable in JavaScript is called "declaring" a variable:

var carName;

After the declaration, the variable is empty (it has no value).

To assign a value to the variable, use the equal sign:

carName = "Volvo";

You can also assign a value to the variable when you declare it:

var carName = "Volvo";

For more information about variables, read our JavaScript Variables Tutorial and JavaScript Scope Tutorial.


Browser Support

Statement
var Yes Yes Yes Yes Yes

Syntax

var varname = value;

Parameter Values

Parameter Description
varname Required. Specifies the name of the variable.

Variable names can contain letters, digits, underscores, and dollar signs.

  • Variable names must begin with a letter
  • Variable names can also begin with $ and _
  • Variable names are case sensitive (y and Y are different variables)
  • Reserved words (like JavaScript keywords) cannot be used as variable names
value Optional. Specifies the value to assign to the variable.

Note: A variable declared without a value will have the value undefined


Technical Details

JavaScript Version: ECMAScript 1

More Examples

Example

Create two variables. Assign the number 5 to x, and 6 to y. Then display the result of x + y:

var x = 5;
var y = 6;
document.getElementById("demo").innerHTML = x + y;
Try it Yourself »

Example

You can declare many variables in one statement.

Start the statement with var and separate the variables by comma:

var lastName = "Doe",
age = 30,
job = "carpenter";
Try it Yourself »

Example

Using variables in loops:

var text = "";
var i;
for (i = 0; i < 5; i++) {
  text += "The number is " + i + "<br>";
}
Try it Yourself »

Related Pages

JavaScript Tutorial: JavaScript Variables

JavaScript Tutorial: JavaScript Scope


❮ JavaScript Statements Reference