I am not getting this java code

Question

Hi everyone, I am struggling to understand what the code below does in the java course on objects. If could explain it to me, it would be greatly appreciated, thanks

System.out.println("We are a making a new pEz dispenser"); PezDispenser dispenser = new PezDispenser("yoad"); System.out.printf("the dispenser character is %s\n", dispenser mCharacterName()); } }

Answer 1 · 2015-10-10T08:11:16Z

October 10, 2015 8:11am

Hi Aaron,

i format you code first:

System.out.println("We are a making a new pEz dispenser");

//System is a class inside Java, its upper cased and classes are upper cased
//then you see a (.) character, you use this to access a method of the System class
//then (.) again and here you access the println method of the System class
//so the Java language has methodes inside classes like System for you, you don´t need to write them all

PezDispenser dispenser = new PezDispenser("yoad"); 

//this one is tricky
//here you create a PezDispenser object and call is dispenser
//you have a class PezDispenser and you can make an instance of that class somewhere in your code
//the instance of the class is the same as an object
//so "dispenser" is an object of PezDispenser class
//a class is a blueprint where you define what an object knows (variables) and can do (methods)
//the new PezDispenser("yoad") line is also nice
//The new keyword is a Java operator that creates the object, it called instantiation = creating an instance/object
// and then : Initialization: The new operator is followed by a call to a constructor, which initializes the new object
//the second PezDispenser is the constructor name
//this is the reason why constructor and class share the same name
//if you look at your constructor, you see a String argument inside the () of the constructor
//so you put your name inside of it ("yoad")


System.out.printf("the dispenser character is %s\n", dispenser.mCharacterName); 

  //one method of the System class  is printf 
  //here you open the parenthesis and whrite your text inside " "
  //%s is a String representation, where you put your %s, there will be your String after compilation
  //so it looks like this ("bla bla %s ", your String variable); , dont forget the (,) and name of your String variable after the ""
 //to use the variables of the PexDispenser object call the object name dispenser and  use (.) to access the member 
// variable mCharacterName
//so dispenser.mCharacterName will return a String representation of mCharacterName

I hope it helps

Grigorij

Answer 2 · 2015-10-10T00:31:03Z

October 10, 2015 12:31am

The first line simply prints We are a making a new pEz dispenser. The second is simply creating a new pez dispenser object and passing a string to its constructor. Then the last gets the name from the newly constructed dispenser object. So for example you would say AronBanerJee aron = new AronBanerJee("Aron"). Then later if you need to know Arons name you would simply call aron.mCharacterName; Although generally the object will have a setter function for this variable. Hope this helps ! =D your friendly mod Doug.

Answer 3 · 2015-10-10T03:05:34Z

October 10, 2015 3:05am

System.out.println("random text"); prints the text and then automatically adds \n to the end of the line.

System.out.printf("random formatted text"); this statement prints out a formatted line, for example you wanted to print out a variable in your text you would add %s in your text System.out.printf("you have %s cookies.", numberOfCookies); this would print out "you have 10 cookies."

I hope this helps as well.

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Aaron Banerjee

Aaron Banerjee

I am not getting this java code

3 Answers

Grigorij Schleifer

Grigorij Schleifer

Doug Ray

Doug Ray

Subhan Khalid

Subhan Khalid