Page 360 - computer science (868) class 11
P. 360
12
RECURSION
Learning Objectives
12.1 Concept of Recursion 12.2 Types of Recursion
12.3 Simple Recursive Methods
The floor art, known by various names - rangoli, kolam, alpana (or alpona), etc., is
a part of Indian tradition drawn daily early in the morning especially on auspicious
events as a sign of welcome. It is a design made of different geometric patterns like
dots, lines, curves, and loops. If we minutely watch the design, then we find that the
whole diagram is a repetition of similar smaller designs placed one beside another
in different patterns.
The basic drawing starts from the dots. By joining the dots in a definite pattern,
we achieve this intricate expression.
The fractals (patterns that repeat forever) are thus created by repeating a simple
process over and over again, or in other words, we can say that they follow the
concept of recursion.
12.1 CONCEPT OF RECURSION
In Java, we can call functions from different functions. Recursion is a programming technique in which a function calls
itself. This technique helps us to break complex problems into simple problems which are easier to solve. A function
that implements recursion is called a recursive function.
Definition
Recursion is a programming technique in which the function calls itself repeatedly until an exit condition called the
base case is achieved.
Let us explain the concept with a simple example.
n
Suppose, we want to find a . If we design a loop then we define a variable whose value changes from 1 to n and
multiplying the term with the product ‘n’ number of times produces the required result as demonstrated below.
p = a × a × a × a ×........... n times.
358358 Touchpad Computer Science-XI

