const Statement (JavaScript)


Declares a block-scoped variable with a constant value.

const constant1 = value1


The name of the variable being declared.


The initial value assigned to the variable.

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.


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();


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.