Slide 1 : Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi PROGRAMMING CONCEPTS - II
Ruchi Sharma
ruchisharma1701@gmail.com
Slide 2 : Contents Quick Recall – Programming Concepts
Components of a programming language
Variables
Constants
Data types & Expressions
Input & Output (I/O) Statements
Conditional statements
Looping constructs Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi
Slide 3 : Quick Recall - Programming Concepts Computer languages can be classified in two broad categories - Low level languages(machine friendly) and High level languages(user friendly)
We usually use HLL for programming to solve a given problem.
While programming, we can use either of the two approaches – procedural or object oriented.
A translator program called Complier converts the HLL program to a LLL program understandable by the computer. Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi
Slide 4 : Computer & User -Who does what ? Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi
Slide 5 : Computer & User -Who does what ? (Contd.) Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi * Note : During processing, the computer also stores the intermediate results, if any, in the memory.
Slide 6 : Components of a Programming Language Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi A programming language has the following components
Variables
Constants
Data types
Expressions
Input & Output statements
Conditional Statements
Looping Constructs
Slide 7 : Variables Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi Variables
Slide 8 : Variables (Contd.) Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi The information is stored in the memory in these cells.
A variable can be understood as “a location name”.
Examples
The statement
x = 10
will store the value 10 in a memory location(depicted by a cell in the figure) named x.
The statement
s = ‘ruchi’
will store the string “ruchi” in the variable s.
Slide 9 : Variables - Facts Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi A variable is allocated memory randomly.
Each variable holds an information of a particular type.
Variables are used in a program to refer to the location(s) where data needed by the program is/are stored.
The value of a variable can be changed i.e. varied(hence the name “VARIable”)
Each time the value of a variable is written into memory, the older one is washed out and the new one is retained.
Slide 10 : Constants Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi A constant is a value that remains unchanged.
A constant can be a numeric constant or a character/string constant. The examples used previously contain the constants 10 (numeric constant) & “ruchi”(string constant) respectively.
A constant value can be assigned to a variable whereas the reverse is not valid. E.g. –
x = 10 is acceptable whereas
10 = x is not !
Slide 11 : Data Types Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi A data type is something which determines the type of data that a variable can hold.
There are three basic types of data that are commonly used integer, real & string.
Related data of same type can be stored in adjacent locations & is called an array. The elements of an array are denoted by the same name but different subscripts.
E g - the roll numbers of the students of a class of 5 can be stored in an array named ROLL & the roll numbers can be referred to as
ROLL[1], ROLL[2], ROLL[3], ROLL[4], ROLL[5].
Slide 12 : Data Types (Contd.) Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi These roll numbers can be assigned values as :
ROLL[1] = 961001
ROLL[2] = 961002
ROLL[3] = 961003
ROLL[4] = 961004
ROLL[5] = 961005
These will be stored in memory in contiguous locations as :
Slide 13 : Expressions Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi An expression is a combination of some operators and operands.
e.g. – In mathematics,
7 x (4 + 19 ) – 34 / 5 is an expression.
(a – b) + c / 60 is an expression.
In computer languages also, the expressions are similar to those in mathematics, just that some symbols are different like, we use * for a sign of multiplication.
Every language specifies an order in which the operators are evaluated in an expression.
Slide 14 : Input and Output Statements Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi Input
An input statement is used to take the input(s) from the user.
The value(s) inputted by the user is/are stored in the designated variable(s) in memory.
e.g. – an input statement in the language C is as under
scanf(“%d”, &x);
after execution of the above statement,
the computer prompts the user to enter a value.
the value entered by the user is stored in the variable x in memory.
Slide 15 : Input and Output Statements (Contd.) Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi Output
An output statement is used to display
an output to the user.
a message to the user.
e.g. – an output statement in the language C is as under
printf(“%d”, x);
after execution of the above statement, the value of the variable x is displayed for the user.
printf(“Hello Boss !”);
after execution of the above statement, the message Hello Boss ! is displayed for the user.
Slide 16 : Conditional Statements Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi In a programming language, there are statements which check for a condition and accordingly the execution flow can be changed. The most common conditional construct is of the format
IF (condition)
THEN
----------------------
ELSE
--------------------
Here, if the condition* evaluates to be “true”, THEN part is executed (& ELSE part is skipped) & if it evaluates to “false”, ELSE part is executed ( & IF part is skipped).
*NOTE - the condition should be a valid expression that can be evaluated to either true or false.
Slide 17 : Looping Constructs Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi Looping constructs are used when we need to repeat a task a number of times or till some condition is met.
A looping construct should have
an initial condition – which starts the loop
an increment – which advances the loop
a termination condition – which helps come out of the loop
The loops used in C language are :
do - while
while
for
Slide 18 : Thank You Ruchi Sharma ruchisharma1701@gmail.com http://www.wiziq.com/tutor-profile/376074-Ruchi