25. Constructors in Review


#1

Hello
My code is this

var rabbit1 = new Rabbit("fluffy");
console.log(rabbit1.describemyself);
var rabbit2 = new Rabbit("happy");
console.log(rabbit2.describemyself);
var rabbit3 = new Rabbit("sleepy");
console.log(rabbit3.describemyself);

My questions are why the console shows only undefined?
And why are these objects coded like this?
And is this like the new Object constructor?


#2

@warriorcodes,
To execute a Method you will have to add a pair of execution-parenthesis-( )
thus
if you are using a console.log() within the Method
you write

rabbit1.describemyself();

If you were using the return statement
you would write

console.log( rabbit1.describemyself() );

But be sure you use the EXACT Method-name as is required by the Instructions....


#3

When i add the parentheses it says Make sure to use Rabbit constructor when creating rabbit2.This exercise has a lot of questions


#4

@warriorcodes,
Could you provide the code of your class object constructor ???


#5

Here it is

function Rabbit(adjective) {
    this.adjective = adjective;
    this.describeMyself = function() {
        console.log("I am a " + this.adjective + " rabbit");
    };
}

// now we can easily make all of our rabbits
var rabbit1 = new Rabbit("fluffy");
console.log(rabbit1.describemyself);
var rabbit2 = new Rabbit("happy");
console.log(rabbit2.describemyself);
var rabbit3 = new Rabbit("sleepy");
console.log(rabbit3.describemyself);

#6

@warriorcodes,

1

Have a close look at

describeMyself

=and=

describemyself

================================================

2

As you are using a console.log() Method within the describeMyself() Method.
you can call the describeMysef() Method
with

rabbit1.describeMyself();

#7

Wait.First of all the describeMyself holly ■■■■ i didn't see that.And second so instead of console.log(blah blah) i just write what u said?


#8

@warriorcodes,
Look at the difference in using the console.log() statement =or= using the return statement.

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 ) );

#9

Thank you so much for all your help.I didn't quite understand that "function talk" article but i'll read it until i will.Thank you