How to do constructors
 

I don't understand constructors. Can anybod help?

The question is:

You are givenÂ* a classÂ*namedÂ* Clock that has one intÂ*instance variableÂ* called hours . Write a constructorÂ* with no parametersÂ* for the classÂ* Clock . The constructorÂ* should set hours to 12 .

I think the answer is:

hours=12;

but I'm worng. Please help.

P.S. One more question:

How do you compare Strings. I think you do:

compareTo(string1,string2)>1;

Am i correct? :rolleyes:

Thanks

Re: How to do constructors
 

I figured out the string stuff ( string1.compareTo(string2)>0; )

Can you just help me on constructors?

Thanks
-- C++

Re: How to do constructors
 

A constructor in essance is a method (with the same name as the Class) that is executed when an instance of the class is created.

For Example:

public class foo {

public int x;

// Constructor
public foo() {
// Do something like
this.x = 45;
}

}

So when you enter in your application:

foo x = new foo() // the constructor foo() is executed.

Re: How to do constructors
 

Thanks.

One more question:

You are givenÂ* a classÂ*namedÂ* Clock that has three instance variablesÂ*: One of typeÂ* intÂ* called hours , another of typeÂ* booleanÂ* called isTicking , and the last one of typeÂ* IntegerÂ* called diff . Write a constructorÂ* for the classÂ* Clock that takes three parametersÂ* -- an intÂ* , a booleanÂ* , and another intÂ* . The constructorÂ* should set the instance variablesÂ* to the valuesÂ* provided.

I think the answer is:

public Clock(int hours, boolean isTicking, int diff){
this.hours = hours;
this.isTicking = isTicking;
this.diff() = diff;
}


Thanks!

Re: How to do constructors
 

Yep, that would be it.

Re: How to do constructors
 

Opps......this.diff()....should be .......this.diff

Re: How to do constructors
 

i still get more errors

Re: How to do constructors
 

Looking at your code:

public Clock(int hours, boolean isTicking, int diff){

    this.hours = hours;

    this.isTicking = isTicking;

    this.diff = diff;

You should have hours, isTicking, and diff defined as class variables too. I did not see that in your code snippet.

To prevent confusion between class variables, and local (method) variables, I add an underscore to my private variables, so that I don't get them confused......ie:

public class CLock {

   // Private variables to the class

   private int hours_;

   private isTicking_;

   private diff_;



    // Your constructor

    public Clock(int hours, boolean isTicking, int diff){

        this.hours_ = hours;

        this.isTicking_ = isTicking;

        this.diff_ = diff;

    } // End of Clock Constructor

} //End of Clock Class

Hoope this clarifies things. If not, submit what errors you are receiving and the code.

Re: How to do constructors
 

My error message is:

Clock.java:11: incompatible types
found : int
required: java.lang.Integer
this.diff=diff;
^
1 error

Thanks