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JavaScript JavaScript Basics (Retired) Creating Reusable Code with Functions Passing an Argument to a Function

brayant benitez
brayant benitez
7,885 Points
Posted by brayant benitez
brayant benitez
7,885 Points

function vs var

Does the "function: keyword work like the "Var" in naming the function? is it defined or undefined? for example:

function returnValue(hello) { return hello; }

var echo = returnValue('greeting');

is returnValue defined?

1 Answer

Ioannis Leontiadis
Ioannis Leontiadis
9,828 Points
Ioannis Leontiadis
Ioannis Leontiadis
9,828 Points

Hello Brayant,

when assigning a value to a variable, the expression on the left is evaluated and then assigned.

So in,

var echo = returnValue('greeting');

the function returnValue() is called, it returns the string "greeting" and then the string is assigned to echo just fine.

When using,

function returnValue(hello){
        return hello;
}

you follow the syntax of,

function NameOfTheFunction(Parameters){
        /*Function Code*/
        return Value;
}

which declares a function which can be called by,

NameOfTheFunction(Arguments);

You can also declare a function like this,

var myFunction = function(Parameters) {
        /*Function Code*/
        return Value;
}

which first creates an anonymous function and then assigns it to myFunction variable. You can then call it like this,

myFunction(Arguments);

As you see these things are quite different. The main difference is that in the first case you have a named function and in the second case you have an unnamed one stored in a variable which is used for reference.

Hope that helped!