{"id":235,"date":"2020-09-01T17:32:25","date_gmt":"2020-09-01T17:32:25","guid":{"rendered":"https:\/\/www.kindsonthegenius.com\/cplusplus\/?p=235"},"modified":"2020-09-01T17:32:25","modified_gmt":"2020-09-01T17:32:25","slug":"c-oop-polymorphism","status":"publish","type":"post","link":"https:\/\/www.kindsonthegenius.com\/cplusplus\/c-oop-polymorphism\/","title":{"rendered":"C++ OOP – Polymorphism"},"content":{"rendered":"

As a word, Polymorphism<\/strong> means ‘many forms’. In OOP, it arise when there are classes that are related to each other via inheritance<\/a>.<\/p>\n

So polymorphism in C++ means that a function with the same name exists in different related classes. Therefore, when a call is made, the particular function that would be executed would depend on the object that invokes it.<\/p>\n

Let’s take for example, a class Fruit. Then three classes derive from fruit: Banana, Apple and Grape. Then each have a function: describe().<\/p>\n

This is shown below<\/p>\n

#include <iostream><\/span>\r\nusing<\/span> namespace<\/span> std;\r\n\r\n\/\/ Base class Fruit<\/span>\r\nclass<\/span> Fruit<\/span> {\r\npublic:<\/span>\r\n\tvoid<\/span> describe(){\r\n\t\tcout<<<\/span>\"Delicious and good for the health\"<\/span>;\r\n\t}\r\n};\r\n\r\n\r\n\/\/ Derived class, Banana<\/span>\r\nclass<\/span> Banana<\/span>:<\/span> public<\/span> Fruit {\r\n\tvoid<\/span> describe(){\r\n\t\tcout<<<\/span>\"Banana: Slender. Yellow when ripe\"<\/span>;\r\n\t}\r\n};\r\n\r\n\r\n\/\/ Derived class, Orange<\/span>\r\nclass<\/span> Orange<\/span>:<\/span> public<\/span> Fruit {\r\n\tvoid<\/span> describe(){\r\n\t\tcout<<<\/span>\"Orange: Round and juicy\"<\/span>;\r\n\t}\r\n};\r\n\r\n\r\n\/\/ Derived class, Grape<\/span>\r\nclass<\/span> Grape<\/span>:<\/span> public<\/span> Fruit {\r\n\tvoid<\/span> describe(){\r\n\t\tcout<<<\/span>\"Grape: Used to make wine\"<\/span>;\r\n\t}\r\n};\r\n<\/pre>\n
In the example above, the describe() member function is called a polymorphous function<\/strong><\/em>.<\/p>\n
Now we have created all the classes. We can then create objects from them and override the describe() in the base case. See Function Overriding<\/a><\/p>\n
\/\/Calling Polymorphous functions<\/span>\r\nint<\/span> main<\/span>() {\r\n\r\n\t\/\/Create different objects<\/span>\r\n\tFruit myFruit;\r\n\tBanana myBanana;\r\n\tOrange myOrange;\r\n\tGrape myGrape;\r\n\r\n\tmyFruit.describe();\r\n\tmyBanana.describe();\r\n\tmyOrange.describe();\r\n\tmyGrape.describe();\r\n\r\n   return<\/span> 0<\/span>;\r\n}\r\n<\/pre>\n
The output of the program is given below:
\n<\/p>\n
Delicious and good for the health \r\nBanana: Slender. Yellow when ripe \r\nOrange: Round and juicy \r\nGrape: Used to make wine \r\n<\/pre>\n
So we can see that the polymorphous functions are called depending on the object that makes the call.<\/p>\n","protected":false},"excerpt":{"rendered":"
As a word, Polymorphism means ‘many forms’. In OOP, it arise when there are classes that are related to each other via inheritance. So polymorphism … <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,35],"tags":[41],"class_list":["post-235","post","type-post","status-publish","format-standard","hentry","category-c-tutorials","category-oop","tag-polymorphism"],"_links":{"self":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts\/235","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/comments?post=235"}],"version-history":[{"count":1,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts\/235\/revisions"}],"predecessor-version":[{"id":236,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/posts\/235\/revisions\/236"}],"wp:attachment":[{"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/media?parent=235"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/categories?post=235"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kindsonthegenius.com\/cplusplus\/wp-json\/wp\/v2\/tags?post=235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}