Difference between revisions of "Java/C2/Method-overloading/English-timed"
From Script | Spoken-Tutorial
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| − | | | + | |To '''overload''' '''constructor''' in '''java''' using '''eclipse'''. |
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| − | |So type '''''void | + | |So type '''''void addTwoNumbers'''''. |
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| − | |Then | + | |Then within curly brackets '''System''' dot '''out''' dot '''println''' '''num1''' plus '''num2.''''' |
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| − | |So in the '''Main''' type '''''Addition i.e the class name ''''' '''''obj''' is equalto '''new''' '''Addition''' parentheses'' semicolon. | + | |So in the '''Main''' method type '''''Addition i.e the class name ''''' '''''obj''' is equalto '''new''' '''Addition''' parentheses'' semicolon. |
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| − | | So what we do is in the method instead of int we will give double. | + | | So what we do is in the method instead of '''int''' we will give '''double'''. |
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| − | | we also know that Java automatically i.e. implicitly coverts int into double. | + | | we also know that Java automatically i.e. implicitly coverts '''int''' into '''double'''. |
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| − | |''Within parentheses '''int n1 '''comma '''int n2''' comma '''int n3.''''' | + | |And''Within parentheses '''int n1 '''comma '''int n2''' comma '''int n3.''''' |
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| − | |This is because we have already declared a method add with no parameters. | + | |This is because we have already declared a method''' add''' with no parameters. |
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| − | |This is how '''method overloading''' is | + | |This is how '''method overloading''' is done in '''java''' |
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Revision as of 16:32, 26 June 2013
| Time' | Narration |
| 00:01 | Welcome to the Spoken Tutorial on method overloading in java. |
| 00:06 | In this tutorial we will learn |
| 00:08 | What is method overloading. |
| 00:10 | And to overload method.
|
| 00:13 | Here we are using
|
| 00:24 | To follow this tutorial you must know |
| 00:26 | how to create methods and |
| 00:29 | To overload constructor in java using eclipse.
|
| 00:32 | If not, for relevant tutorials please visit our website which is as shown,
(http://www.spoken-tutorial.org) |
| 00:39 | What is method overloading? |
| 00:42 | Define two or more methods with same name within a class. |
| 00:46 | They must differ in number or types of parameters. |
| 00:50 | These methods are called overloaded methods. |
| 00:54 | The process is called method overloading. |
| 00:57 | Let us now see how to overload method. |
| 01:00 | In eclipse, I have a class Addition. |
| 01:06 | Inside the class we will declare two integer variables. |
| 01:10 | So type int a is equalto 10 and int b is equalto 5. |
| 01:19 | Let us create a method to add these two integers. |
| 01:23 | So type void add parentheses. |
| 01:30 | Within curly brackets type System dot out dot println. |
| 01:40 | Inside parentheses a+b. |
| 01:44 | So this method will give us the sum of two integer variables. |
| 01:50 | Let us create another method which takes two parameter. |
| 01:55 | So type void addTwoNumbers. |
| 02:04 | Within parentheses int num1 comma int num2. |
| 02:14 | Then within curly brackets System dot out dot println num1 plus num2. |
| 02:35 | So this method will give us the sum of two values that are passed test argument to this methods. |
| 02:44 | Let us create an object of the class and call the methods. |
| 02:49 | So in the Main method type Addition i.e the class name obj is equalto new Addition parentheses semicolon. |
| 03:13 | ThenObj.add |
| 03:18 | AndObj.addTwonumbers within parentheses. |
| 03:31 | we will pass two arguments. |
| 03:33 | Suppose if we pass floating point values. |
| 03:37 | So type 2.5 comma and an integer 3. |
| 03:45 | We get an error which states that , the method addTwoNumbers int comma int of the class addition is not applicable for the argument double comma int. |
| 03:57 | So what we do is in the method instead of int we will give double. |
| 04:06 | So replaceintby double. Save the file |
| 04:12 | we see that the error is resolved. |
| 04:17 | we also know that Java automatically i.e. implicitly coverts int into double. |
| 04:24 | So here we can pass an integer arguments as well. |
| 04:28 | Now Save and Run the program |
| 04:32 | In the output we see the sum of two integers variables, |
| 04:37 | And the sum of two numeric arguments that we passed. |
| 04:43 | Now we see that both the method performs same operation. |
| 04:50 | The difference is that the first method has no parameter. While the second method has parameters. |
| 05:00 | So in such case java provides us with method overloading. |
| 05:05 | So what we do is give same name to both the methods. |
| 05:09 | So replace addTwoNumbers with add also change here. |
| 05:29 | We will define one more method with same opearation. |
| 05:33 | So type void add. |
| 05:38 | AndWithin parentheses int n1 comma int n2 comma int n3. |
| 05:51 | So we have given three parameters. |
| 05:54 | One Within curly brackets System dot out dot println. |
| 06:03 | Within parentheses n1 plus n2 plus n3. |
| 06:11 | So this method will give sum of three numbers. |
| 06:17 | let us call this method. |
| 06:19 | So type obj dot add 1 comma 5 comma 4 |
| 06:35 | Save' and Run |
| 0639 | In the output we see the sum of three number i.e10 |
| 06:47 | So Java compiler overloads the proper method depending on the parameters. |
| 06:52 | It checks the number and type of parameter passed |
| 06:57 | So as a programmer we dont have worry about the method name. |
| 07:01 | Nor even the type or number of argument we passed. |
| 07:05 | We can create one more method which append strings. |
| 07:11 | So we will create one more overload method |
| 07:15 | type void add String s1 comma String s2. |
| 07:29 | Within curly brackets System dot out dot println. |
| 07:41 | Within parentheses s1 plus s2. |
| 07:45 | And we will call this method. |
| 07:50 | So type obj dot add. |
| 07:55 | Within parentheses in double quotes Hello comma in double quotes space World. |
| 08:07 | Now Save and Run the program. |
| 08:12 | So in the output we see Hello space World. |
| 08:16 | So the add method with two string arguments, appends the string. |
| 08:21 | Suppose now we declare add method with return type. |
| 08:27 | So type int add parentheses no parameter and curly brackets. |
| 08:40 | We get an error it states that duplicate method add in type addition |
| 08:48 | This is because we have already declared a method add with no parameters. |
| 08:54 | So remember that to overload method the parameters must differ. |
| 08:5 | Having different return types will not overload the method. |
| 09:03 | So remove this method and Save the file. |
| 09:09 | This is how method overloading is done in java |
| 09: 16 | So in this tutorial we learnt, |
| 09:18 | About method overloading. |
| 09:20 | To overload method. |
| 09:22 | And advantage of method overloading. |
| 09:25 | For self assessment, create a method subtract that subtract that number |
| 09:31 | Overload it.
|
| 09:33 | To know more about the Spoken Tutorial Project |
| 09:36 | Watch the video available at http://spoken-tutorial.org/What_is_a_Spoken_Tutorial |
| 09:42 | It summarizes the Spoken Tutorial project |
| 09:45 | If you do not have good bandwidth, you can download and watch it
|
| 09:48 | The Spoken Tutorial Project Team |
| 09:50 | Conducts workshops using spoken tutorials |
| 09:52 | Give certificates to those who pass an online test |
| 09:56 | For more details, please write to contact@spoken-tutorial.org
|
| 10:01 | Spoken Tutorial Project is a part of the Talk to a Teacher project |
| 10:05 | It is supported by the National Mission on Education through ICT, MHRD, Government of India |
| 10:11 | More information on this Mission is available at
http://spoken-tutorial.org/NMEICT-Intro
|
| 10:19 | We have come to the end of this tutorial. |
| 10:21 | Thanks for joining. |
| 10:22 | This is Prathamesh Salunke signing off. Jai Hind. |
Contributors and Content Editors
Devisenan, Gaurav, Jyotisolanki, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha
