# isNaN function outcome opposite expected. Why?

#1

In the exercises we're supposed to us isNaN to text if the number is a number. If it is a number I assume isNaN returns false. So I have written my code to inform a user that the input is not a number if isNaN returns true.

Problem is, isNaN is returning true for numbers and giving me an error message. If I change the condition to false, I am passed with a green go to the next....

I expect isNaN (is not a number) should issue a true response for string and a false response for a number. Am I misunderstanding or is there some other problem.

My code is below. I'm soooo confused.

``````var isEven = function(number) {
if (isNaN(isEven) === true ) {
return "That's not a number.";
} else if (isEven %= 2) {
return true;
} else {
return false;
};
};``````

#2

@mike.rodygmail.com,
You are confused with what a =function='s PARAMETER does......!!!!

### the FUNCTION talk

``````var myFunc = function( param1, param2) {
//Begin of  anonymous FUNCTION-BODY
//VARIABLE -myFunc- has an -anonymous function- assigned
//this -anonymous function- has 2 PARAMETERS param1 and param2
//param1 and param2 PARAMETERS are used
//as -local- VARIABLES throughout the FUNCTION-BODY

console.log( param1 + " and " + param2 ) ;

//End of anonymous FUNCTION-BODY
};``````

If you want to call/execute the anonymous function
you will have to add a pair of parentheses to the variable myFunc
like
myFunc();
As the anonymous function was defined
as having 2 parameters
you have to provide 2 arguments
in our case 2 string VALUES "Alena" and "Lauren"
like
myFunc("Alena","Lauren");

some quotes from the outer-world:

**argument is the value/variable/reference being passed in,
parameter is the receiving variable used within the function/block**

OR

**"parameters" are called "formal parameters",
while "arguments" are called "actual parameters".**

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

### function with 1 parameter using return-statement

``````var myFunction = function( param1 ) {
//Begin of FUNCTION-BODY
//myFunction =function= has 1 PARAMETER param1
//this param1 PARAMETER is used as a -local- VARIABLE
//throughout the FUNCTION-BODY

return param1;

//End of FUNCTION-BODY
};``````

you have defined a myFunction function
which takes 1 parameter param1
this param1 parameter is used
as a variable throughout the FUNCTION-BODY.

If you want to call/execute this myFunction function
and this myFunction function was defined
as having 1 parameter param1
you will have to provide 1 argument
in our case a "number VALUE" 4
myFunction( 4 );

some quotes from the outer-world:

**argument is the value/variable/reference being passed in,
parameter is the receiving variable used within the function/block**

OR

**"parameters" are called "formal parameters",
while "arguments" are called "actual parameters".**

#### ============================================

As you are using the return-statement in your myFunction function
you will only get a return-value no-display.
You can however capture this return-value in a variable
and then use the console.log()-method to do a display.

``````var theResult = myFunction( 4 );
console.log( theResult );``````

OR directly

``console.log( myFunction( 4 ) );``