ஜாவா இன்ஹரிடன்ஸ்

class ù¤¬ùð¢ ðø¢ø¤ò ªî÷¤õ£ù Syntax -ä

ð£ó¢ð¢«ð£ñ¢.

Syntex:

[modifiers] class <class name> [extend <superclass>] [implements

<interfaces>]

âð¢ªð£¿¶«ñ èì¢ì¬÷è÷¤ù¢ Syntax -è¬÷ ð®è¢°ñ¢ ªð£¿¶ [ ] bracketsè÷¤

ù¢ à÷¢ Þ¼ð¢ð¬õ Option -è÷¢ Ý°ñ¢. Üî£õ¶ Üõø¢¬øð¢ ðòù¢ð´î¢îô£ñ¢

Üô¢ô¶ ðòù¢ð´î¢î£ñ½ñ¢ Þ¼è¢èô£ñ¢. Þ¶õ¬ó ï£ñ¢ ð£ó¢î¢î â´î¢¶è¢

è£ì¢´è÷¤ô¢ [modifiers], [extend super class] ñø¢Áñ¢ [implement interface] ºîô£ù

Þùé¢è÷¢ ðòù¢ð´î¢îð¢ðìõ¤ô¢¬ô. ܬõ åõ¢ªõ£ù¢Áñ¢ ªõõ¢«õÁ

29

ðòù¢ð£´è¬÷è¢ ªè£í¢ì¬õ. âù«õ Üõø¢¬øî¢ îù¤ â´î¢¶è¢è£ì¢´è÷¢

Íôñ¢ Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢.

Inheritance

Object Oriented Programming º¬øò¤ô¢ Þ¼è¢è¤ù¢ø ºè¢è¤òñ£ù

ðòù¢ð£´è÷¤ô¢ Inheritance -ñ¢ åù¢Á. Þï¢î º¬øò¤ù¢ Íôñ¢ Þóí¢´ classèÀè¢

褬ìò¤ô¢ å¼ Þ¬íð¢ð¤¬ù à¼õ£è¢°è¤ù¢«ø£ñ¢. Þîù¢ð® Þóí¢´

class -è÷¤ô¢ åù¢ø¤¬ù super class âù¾ñ¢ ñø¢ªø£ù¢ø¤¬ù subclass âù¾ñ¢

ܬöè¢è¤ù¢«ø£ñ¢.

â´î¢¶è¢è£ì¢ì£è father âù¢ªø£¼ class-ñ¢ child âù¢Âñ¢ ªðòó¤ô¢ å¼

class-ñ¢ Þ¼ð¢ðî£è ¬õ袪è£÷¢«õ£ñ¢. father class -ù¢ à÷¢ father name, age,

occupation ºîô£ù å¼ îîò¤¬ùð¢ðø¢ø¤ò îèõô¢è¬÷ê¢ «êèó¤î¢¶

¬õè¢èð¢ð좮¼è¢è¤ù¢øù. child class -à÷¢ child name, age, hobbies ºîô£ù å¼

ñèù¤¬ùð¢ðø¢ø¤ò îèõô¢è÷¢ «êèó¤î¢¶ ¬õè¢èð¢ð좮¼è¢è¤ù¢øù âù¢Á

ªè£÷¢Àé¢è÷¢. Þï¢î Þóí¢´ class -è÷¢ îù¤î¢îù¤ò£è õ¬óò¼è¢èð¢

ð좮¼ð¢ð¤ù¢ åù¢Áìù¢ åù¢Á ªî£ìó¢¹ Þ¼è¢è£¶ Üô¢ôõ£? Þð¢ªð£¿¶

Child class -ø¢è¢° å¼ Object -®¬ù à¼õ£è¢°è¤ù¢«ø£ñ¢ âù¢Á ¬õè¢

ªè£÷¢Àé¢è÷¢. Üï¢î child object -ù¢ à÷¢ ïñ袰 father -ø¤¬ùð¢ îèõô¢è÷¢

õó«õí¢´ñ¢ âù¢Á õ¤¼ñ¢ð¤ù£ô¢ Üîø¢° ï£ñ¢ inheritance º¬øò¤¬ùè¢

¬èò£÷ «õí¢´ñ¢. Þîø¢° extends âù¢Âñ¢ èì¢ì¬÷ð¢ ðòù¢ð´è¤ù¢ø¶.

Listing 2.3

class father

{

String fname;

int fage;

public void assign(String tfname, int tfage)

{

fname=tfname;

fage=tfage;

}

public void view()

{

System.out.println(“Father’s Name : “ + fname);

System.out.println(“Father’s Age : “ + fage);

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System.out.println(“”);

}

}

class child extends father

{

String cname;

int cage;

public void store(String tcname, int tcage)

{

cname=tcname;

cage=tcage;

}

public void display()

{

System.out.println(“Child’s Name : “ + cname);

System.out.println(“Child’s Age : “ + cage);

System.out.println(“”);

}

}

class school

{

public static void main(String arg[])

{

child allen = new child();

allen.assign(“Sebastian Raj”,30);

allen.store(“Allen Smith”,3);

allen.view();

allen.display();

}

}

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Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ father âù¢Âñ¢ class Ýù¶ ºîô¤ô¢

â¿îð¢ð좮¼è¢è¤ù¢ø¶. Üî¬ùî¢ ªî£ìó¢ï¢¶ child âÂñ¢ class è¦ö¢è¢èí¢ìõ£Á

õ¬óò¼è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢.

class child extends father

{

.....

}

Þ颰 extends father âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¤ù¢ Íôñ¢ child class Ýù¶

father class àìù¢ Þ¬íè¢èð¢ð좮¼è¢è¤ù¢ø¶. âù«õ Þð¢ªð£¿¶ father

class Ýù¶ child class ¬ìò superclass Ýè ªêòô¢ð´è¤ù¢ø¶. Üô¢ô¶

base Class âù¢Áñ¢ Ãøô£ñ¢.

Þîù¢ð® ï¦é¢è÷¢ âð¢ªð£¿ªîô¢ô£ñ¢ child class -ø¢° Object -´è¬÷

à¼õ£è¢°è¤ù¢ø¦ó¢è«÷£ Üð¢ªð£¿ªîô¢ô£ñ¢ super class Ýù father -ù¢ Object

åù¢Áñ¢ î£ù£è à¼õ£è¢èð¢ð좴 õ¤´ñ¢. ï£ñ¢ îù¤ò£è father class -ø¢è¢°

ªèù¢Á Object -´è¬÷ à¼õ£è¢è «õí¢®òî¤ô¢¬ô. «ñ½ñ¢ Þï¢î ¹«ó£è¤ó£ñ¤ô¢

child allen = new child( );

âù¢Á ªè£´î¢¶ allen âù¢Âñ¢ ªðòó¤ô¢ child class -ù¢ Object -¬ù à¼õ£è¢è¤

ò¤¼è¢è¤ù¢«ø£ñ¢. Þ颰

allen.store(...)

allen.display( )

ºîô£ù¬õ Child Class -¬ìò function -è÷¢ Ý°ñ¢.

allen.assign(...)

allen.view( )

ºîô£ù¬õ father class -ù¢ function -è÷ Ý°ñ¢. Þï¢î function -è÷¢ allen

âù¢Âñ¢ child class -ù¢ Íôñ¢ Þò颰è¤ù¢ø¶ âù¢ðî¬ù Üø¤õîù¢Íôñ¢

Inheritance âõ¢õ£Á Þò颰è¤ù¢ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢.

°ø¤ð¢¹

Java -õ¤¬ù𢠪ð£¼î¢îõ¬óò¤ô¢ åõ¢ªõ£¼ °ø¤ð¢ð¤ì¢ì «õ¬ôò¤¬ùê¢

ªêò¢õîø¢°ñ¢ âù¢Á ðô¢«õÁ class -è÷¢ â¿î¤ ¬õè¢èð¢ð좴 Þ¼è¢è¤ù¢øù.

Üï¢î class -è¬÷ ï£ñ¢ «î¬õ被èø¢ø£ó¢«ð£ô Object -´è÷£è à¼õ£è¢è¤

ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ «õí¢´ñ¢. Üô¢ô¶ ï£ñ£è å¼ class -¬ù à¼õ£è¢è¤

Üï¢î class -ø¢° ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø Java class -è÷¤¬ù extend

èì¢ì¬÷ò¤¬ùð¢ ðòù¢ð´î¢î¤ Inheritance ªêò¢¶ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢