const Statement (JavaScript)

Declares a block-scoped variable with a constant value.

Syntax

const constant1 = value1  

Parameters

constant1
The name of the variable being declared.

value1
The initial value assigned to the variable.

Remarks

Use the const statement to declare a variable with a constant value, the scope of which is restricted to the block in which it is declared. The value of the variable cannot be changed.

A variable declared using const must be initialized when it is declared.

Example

The following example illustrates the use of the const statement.

var c = 10;  
{  
    const c = 2;  
   // At this point, c = 2.  
}  
// At this point, c = 10.  

// Additional ways to declare a variable using const.  
const name = "Thomas Jefferson";  
const answer = 42, numpages = 10;  
const myarray = new Array();  

Requirements

Supported in the Internet Explorer 11 standards document mode. Also supported in Store apps (Windows 8.1 and Windows Phone 8.1). See Version Information.
Not supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards, Internet Explorer 10 standards. Not supported in Windows 8.

See Also

let Statement
new Operator
Array Object
Variables