Java/C2/Default-constructor/English-timed

Time	Narration
00:02	Welcome to the Spoken Tutorial on Default constructor in java.
00:07	In this tutorial, we will learn:
00:10	About the default constructor.
00:12	And to create a constructor.
00:15	Here we are using: Ubuntu version 11.10 Java Development Environment jdk 1.6 and Eclipse 3.7.0
00:26	To follow this tutorial, you must know
00:29	how to create a class and the object of the class in java using eclipse.
00:34	If not, for relevant tutorials, please visit our website which is as shown.http://www.spoken-tutorial.org
00:42	Constructor is used to initialize the instance variables.
00:46	It is called at the creation of new object.
00:50	Let us now see how a constructor is defined in java.
00:55	So, in the eclipse, I have already created a java file Student.java.
01:02	In the Student class we will declare two variables.
01:07	So type int roll_number semi-colon and String name semicolon.
01:20	Now let us create a method.
01:22	So, type: void studentDetail().
01:33	Within curly brackets, type: System dot out dot println roll_number;
01:50	Then System dot out dot println name;.
02:03	Now in main method we will call this method.
02:08	So, let us create an object and call the method.
02:14	So, type: Student object name stu equal to new Student().
02:28	Then stu dot method name i.e studentDetail.
02:41	Save and Run the program.
02:46	We see the output 'zero' and 'null'.
02:49	So, the int variable roll_number has been initialized to its default value 'zero'.
02:56	And the String name has been initialized to its default value 'null'.
03:02	If we do not define a constructor then a default constructor is created.
03:08	Default constructor has no parameters.
03:11	It initializes the instance variables to their default value.
03:16	Now let us define a constructor.
03:18	So, type: Student S capital parenthesis and curly brackets.
03:30	Remember, the Constructor has the same name as the 'class name' to which it belongs.
03:38	Constructors are also similar to methods but there are some important differences.
03:44	Save and Run the program.
03:48	We see the same output.
03:51	This is because the constructor that we defined is same as having no constructor.
03:58	But here, no default constructor is created because we have defined a constructor.
04:06	Now, let's give values to our variables.
04:11	So, inside the constructor type: roll_number equal to ten semicolon.
04:25	And name equal to within double quotes Raman.
04:35	Now Save and Run the program.
04:43	We see in the output that the roll_number is ten and the name is Raman.
04:50	So, the constructor initializes the instance field.
04:55	Now, let us see some differences between method and a constructor.
05:01	Constructor does not have a return type.
05:05	whereas method has a return type.
05:10	Constructor is called using the new operator.
05:16	whereas the method is called using the dot operator.
05:21	So, these were some differences between constructor and method.
05:29	So, in this tutorial, we have learnt:
05:32	About the default constructor.
05:34	To define a constructor.
05:36	And Differences between method and constructor.
05:41	For self assessment,
05:42	create a class Employee with variables and a method to display variables.
05:47	And create a constructor for the class Employee.
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06:38	This brings us to the end of the tutorial.
06:40	Thanks for joining.
06:42	This is Prathamesh Salunke, signing off. Jai Hind.

Contributors and Content Editors

Gaurav, PoojaMoolya, Sandhya.np14, Sneha