programming techniques

Question 1

what is the difference between passing parameters BY VALUE and BY REFERENCE ?

Answer 1

passed by reference is when the funtion will call its memory location of the variable , passed by value this is when the function will receive a copy of the variable

Question 2

what is meant by modular programming ?

Answer 2

• Modular programming is when a large program is broken down to smaller tasks which are easier to test and maintain.

Question 3

what are some advantage of modular programming?

Answer 3

-easier to test
-easier to maintain
-modules can be reused
-a team of programmers can work on modules

Question 4

explain why using local variables makes a large program easier to maintain ?

Answer 4

-There are no unexpected side effects as its independent than other modules.

Question 5

Describe one disadvantage of a recursive routine compared with an iterative routine?

Answer 5

disadvantage :
-Recursion is less memeory efficient
-consistent recursion could cause a stack overflow

Question 6

what is A WATCH in an ide ?

what is a trace in an ide ?

Answer 6

a watch -any item of data that a programmer wants to observe runs on its own.

A trace can be set so that a programmer can step through a program , line by line to trace the execution

Question 7

in OOP what is a :
class ?
constructor ?
Instantiation?

Answer 7

a class is a blue print for objects

a constructor is a method/procedure which allows new objects in the class to be created.

instantiation is a statement which creates an object belonging to a particular class

Question 8

what is an IDE ?

Answer 8

an IDE is a program that provides a set of tools and designed to maximise a programmers productivity.

Question 9

what does an IDE have ?

Answer 9

• code editors
  -error diagnostics
  -translators

Question 10

what is the difference between a whileloop and a loop ?

Answer 10

A while loop will keep repeating until the correct
password has been input // condition is met .
A for loop will only repeat a certain number of
times

Question 11

what is a differnce between global and local variable ?

Answer 11

Global variable is visible throughout a program whereas local variable is visible only in module/construct where it is created/declared

Question 12

what is a function ?

Answer 12

it returns a value often called inline

Question 13

what is polymorphism?

what is encapsulation?
what are the benefits of encapsulation?

Answer 13

Polymorphism is the ability of a programming language to present the same interface for several different underlying data types.

encapsulation refers to the bundling of data, along with the methods that operate on that data, into a single unit.

Benefits:
- hiding data
-Easy to reuse
-more flexible

Question 14

what is meant by intractable?

Answer 14

intractable problems are problems for which there exist no efficient algorithms to solve them.

Question 15

what are the advantages of OOP?

Answer 15

encapsulation - hides unnecessary details , so only necessary data is shown
- inheritance- links classes that are similar , which makes it easier to refer to when coding

Question 16

what is procedual programming?

Answer 16

this is a type of programming paradigm , where a program is built from one or more subroutines. e.g global,local or procedures and functions.

Question 17

explain how backtracking is used in traversal?

Answer 17

-It starts at the root and goes the bottom of the branch, and stores all the visited lists into a stack
-when it cannot go further, it backtracks to other nodes
-it then goes to another branch in the binary tree and back tracks from the beginning.

Question 18

explain how backtracking is used in traversal?

Answer 18

-It starts at the root and goes the bottom of the branch, and stores all the visited lists into a stack
-when it cannot go further, it backtracks to other nodes
-it then goes to another branch in the binary tree and back tracks from the beginning.

Question 19

explain why insertion sort might use less memory than merge sort?

Answer 19

An insertion sort may use less memory as a merge sort as
- merge sort might create new arrays
-insertion sort is an in-place algorithm

Question 20

what are the benefits and drawback of decalring an array as a global variable instead of local ?

Answer 20

Benefit :
-can be accessed from any function/ anywhere in the program
-you don’t need to return a value
-vairbale doesn’t need to be passed by parameter

drawback:
-incrases memry usage
-unwanted altercations within the function may lead to side affects.