Recursion

Question 1

what is recursion

Answer 1

when a function calls itself
this produces repetition

Question 2

when is recursion used

Answer 2

to make code repeat
as an alternative to iteration

Question 3

what are the advantages and limitations of recursion

Answer 3

+ shorter and simpler code

• each recursion uses up space in memory

Question 4

structure of a recursive function

Answer 4

• header w/ name of func and parameters
• base case - an if statement, ends as the final return
• the name of the function itself with any other parameters

Question 5

the base case

Answer 5

an if statement

typically at the top of a recursive function defenition

if the test is true , the recursion stops

Question 6

how are parameters used in recursuon

Answer 6

pass values along the chain of functions that open in memory

Question 7

how to convert a recursive function to iteration

Answer 7

• turn the if line of the base case into the header of a while loop, reversing the logic
• indent the commands inside the while loop
• delete recursive lines

Question 8

how to convert an iterative function to recursion

Answer 8

• convert the header of the while loop into a base case (if statement) , reversing the logic

add a recursive line at the end of the program

consider whether you need to use parameters

Question 9

similarity between recursion and iteration

Answer 9

used to repeat blocks of code

Question 10

differences between recursion and iteration

Answer 10

recursive function often solves a problem in fewer lines of code, but uses more memory

iterative function overrwrites same area of memory repeatedly, using less space

iterative functions use more lines to solve the problem