JavaScript Function Scope

In JavaScript there are two types of scope:

JavaScript has function scope: Each function creates a new scope.

Scope determines the accessibility (visibility) of these variables.

Variables defined inside a function are not accessible (visible) from outside the function.

Local JavaScript Variables

Variables declared within a JavaScript function, become LOCAL to the function.

Local variables have Function scope: They can only be accessed from within the function.

// code here can NOT use carName

function myFunction() {
var carName = "Volvo";

// code here CAN use carName

}

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Since local variables are only recognized inside their functions, variables with the same name can be used in different functions.

Local variables are created when a function starts, and deleted when the function is completed.

A variable declared outside a function, becomes GLOBAL.

A global variable has global scope: All scripts and functions on a web page can access it.

var carName = "Volvo";

// code here can use carName

function myFunction() {

// code here can also use carName

}

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