A pseudo code is an informal was to describe a program
Pseudo code is not a computer program
Pseudo code can use natural language or compact mathematical notation
It is a rough sketch of the actual program
Syntax of Pseudo code
No standard for pseudo code syntax exists
So we don’t have to follow any strict syntax like computer programming language
Pseudo code vary in style from author to author
Pseudo code commonly borrows its syntax from popular programming languages like C, Fortran, Pascal, Java etc.
Module
We write algorithms to solve problems
Algorithms are broken down into modules
Some problems are simple so they have simple algorithms and few modules
Some problems are complex so they have complex algorithms which have more modules
Notation
Name
We can give any reasonable name to an algorithm module. Example
Sum()
For algorithm with more than one word name we will use camel-case. Example
FindHighScore()
Note! First letter of every word is in upper-case. Camel-case is also used in which each word starts with a capital letter except the first word. Example
findTime()
Variable name
We will use lowercase for variable name. Example
name
age
For more than one word variable we will use camel-case. Example
highScore
isGameOver
Note! Variable name will start with lower-case.
Initializing variable
For initializing variable we will use the word Set Example
Set score = 0;
Initializing several variables
Set x = 0, y = 0, score = 0, isGameOver = false;
Note! Above statement will be executed from left to right.
Input
Data may be input and assigned to variable using Read statement.
Read: variable list
Example
Read: x;
Or
Read: x, y, z;
Note! Value will be assigned from left to right.
Output
Message and data in variables may be output by using Write or Print statement.
Write: Message and/or variable list
or
Print: Message and/or variable list
Example
Write: “Hello World”; //message
Print: “Value of x = ”, x; //message and variable
Note! Message and variable is separated by comma , [similar to Python programming] We can also use the + sign to join message and variable [similar to JavaScript]
Begin and End
Algorithm will start with a Begin statement and will end with an End statement.
Completion of Algorithm
Algorithm is completed with the execution of the last instruction. However, we can terminate the execution at any stage using Exit instruction.
Sub Algorithm
We generally divide complex problem into small manageable sub problems and then we develop algorithm for each of the sub problems, called sub algorithm.
About Sub Algorithm
Sub algorithm is also referred as module
Sub algorithm can not run on its own
We need to call it either from main algorithm or from another sub algorithm
Sub algorithm is given a name
It can also have parameter list
It can return value using return statement
Calling an Algorithm Module
We will use the Call statement to call any algorithm module from another module.