CSE 1201: Structured Programming Language

Course Title: Structured Programming Language Course Code: CSE 1201
Batch: CSE-14
Trimester: Fall-2020
Presented by: Presented for:
Stein Joachim Rebeiro (202120001) Abul Hasnat Md. Saiful Islam,
Zubayer Farazi (202120003) Associate Professor,
Raisa Fabiha (202120004) Chairman, Department of CSE,
Notre Dame University, Bangladesh
Department: Computer Science & Engineering

Programing Language Defination, Application
History of C Programing Language
Improtance of Flow Chart
Flow Chart, Pseudo Code (Algorithm Example)
Control Structure (loop) / break / Continue
Decision Making & Branching
Operator, Explanation with Appropriate Code
Data Type
Variable, Constants, Identifier, Rules
TOPICS:

PROGRAMMING LANGUAGE DEFINITION:
• A FORMAL LANGUAGE COMPRISING A SET OF INSTRUCTIONS
• THIS LANGUAGE PROVIDES A WAY OF TELLING A COMPUTER WHAT
OPERATIONS TO PERFORM.
• EACH PROGRAMMING LANGUAGE HAS A DIFFERENT SET OF SYNTAX
RULES
• USED TO CREATE PROGRAMS THAT CONTROL THE BEHAVIOR OF A
MACHINE

TYPES OF LANGUAGES:
Programming language
Low level language High level language
Machine Language Assembly Language
C,C++, Fortran, Java,
Python, Basic, Pascal….

Machine language:
 The native language of the computer
 0 and 1 these two binary digits are used to write this language
Assembly Language:
 Little easier than machine language
 Replaces 1 and 0s with English instructions
 Use symbols or Collection of mnemonic codes
 It has command like: ADD, MUL, DIV, INP etc.
High Level Language:
 Close to human language
 Easy to learn
 C, C++, Fortran, Cobol etc. uses compiler
 Python, Basic etc. uses interpreter

Applications of Programming Language:
• To create software
• Software can be made for calculator or to do
mathematical problems
• To create web applications
• In software development
• Games and animations with 3d effects
• For game design

HISTORY OF C PROGRAMMING LANGUAGE:
• C was evolved from ALGOL, BCPL and B
• In 1972 Dennis Ritchie at Bell Laboratories writes C
• It was developed along with the UNIX operating system
• Added new features and concept like “data types”
• In December 1989 American National Standards Institute (ANSI) approved a
version of C which is now known as ANSI C

HISTORY OF C PROGRAMMING LANGUAGE:
Language Developed Year Developed By
ALGOL 1960 International Group
BCPL 1967 Martin Richards
B 1970 Ken Thompson
C 1972 Dennis Ritchie
K&R C 1978 Kernighan and Ritchie
ANSI C 1989 ANSI Committee
ANSI/ISO C 1990 ISO Committee
C99 1999 Standard Committee
C11 2011 Standard Committee

FLOW CHART:
• Diagrammatic representation of logic for solving task
• Drawn using boxes of different shapes with lines connecting them to show the
flow of control
• Make logic of program clearer in a visual form
• Diagrammatic representation forms a common medium of communication
• Drawn using different kinds of symbols.

BASIC FLOW CHART SYMBOLS, NAME & FUNCTION:

CONTROL STRUCTURE OF FLOW CHART:

IMPORTANCE OF FLOW CHART:
A Flowchart -
• shows logic of an algorithm
• emphasizes individual steps and their interconnections
• Helps to control flow from one action to the next

PSEUDO CODE:
• Consists of short, readable and formally-styled English language used for explaining
an algorithm.
• Does not include details like variable declarations, subroutines etc.
• Short-hand way of describing computer program
• Not based on any programming language
• Uses structured constructs of programming language but is not machine readable
• Cannot be compiled or executed
• No standard for syntax of pseudo code exists

ALGORITHM:
• Ordered sequence of finite, well defined, unambiguous instructions for
completing a task.
• English-like representation of logic to solve problem
• Step-by-step procedure for solving problem
• For a particular task, different algorithms can be written
**We need to select an algorithm based on advantages and disadvantages.
Different Algorithms would typically lead to trade off between memory requirements and
execution.

Example of Algorithm with Flow Chart:

VARIABLES:
• In programming, a variable is a container (storage area) to hold data.
• To indicate the storage area, each variable should be given a unique name . Variable
names are just the symbolic representation of a memory location.
• Each variable in C has a specific type, which determines the size and layout of the
variable's memory; the range of values that can be stored within that memory; and the
set of operations that can be applied to the variable.
• The name of a variable can be composed of letters, digits, and the underscore character.
It must begin with either a letter or an underscore. Upper and lowercase letters are
distinct because C is case-sensitive.

RULES OF VARIABLES:
• A variable name can only have letters (both uppercase and lowercase letters), digits, dollar sign($) and
underscore.
• The first letter of a variable should be either a letter or an underscore.
• Keywords, ‘&’, Variable name starting with numbers, hyphen(-) ; no special symbols are valid.
Note: We should always try to give meaningful names to variables. For example: First Name is a better
variable name than fn.
**C is a strongly typed language. This means that the variable type cannot be changed once it is
declared.**

CONSTANTS:
• C Constants are also like normal variables. But, only difference is, their values can
not be modified by the program once they are defined.
• Constants refer to fixed values. They are also called as literals
• Constants may be belonging to any of the data type.

RULES OF CONSTANTS:
• By “const” keyword or by “#define” preprocessor directive, a constant is declared
in C program.
• It can either be positive or negative. If no sign is declared, then the constant is
assumed to be positive.
• No commas or blanks are allowed within a constant.
• Character constant is a single alphabet, a single digit or a single special symbol
enclosed within single quotes.
• The allowable range for integer constants is -32768 to 32767.
• If we try to change constant values after defining in C program, it will show error.

IDENTIFIER:
• Identifier refers to name given to entities such as variables, functions, structures
etc. Variable and identifiers are almost the same but identifier can be used in a
larger scale. Such as- “Array”.
• Identifiers must be unique. They are created to give a unique name to an entity to
identify it during the execution of the program. For example:
int money; double Balance;
Here, money and Balance are identifiers.
• Also identifier names must be different from keywords. We cannot use `int` as an
identifier because int is a keyword.

RULES OF IDENTIFIERS:
• A valid identifier can have letters (both uppercase and lowercase letters), digits and
underscores.
• The first letter of an identifier should be either a letter or an underscore.
• Keywords like int, while etc. cannot be used as identifiers.
• There is no rule on how long an identifier can be.
**Any name can be chosen as an identifier if we follow the above rules. However, giving
meaningful names are recommended as identifiers that make sense.**

EXAMPLE OF VARIABLE, CONSTANT & IDENTIFIER:
If we use variable_1[5] then it will become an array. Even then
it will be consider as an identifier but we cannot declare it as
a variable anymore. And this is the difference between
identifier & variable.

DATA TYPES:
• Data types in c refer to an extensive system used for declaring variables or
functions of different types. The type of a variable determines how much space it
occupies in storage and how the bit pattern stored is interpreted.
• It determines the type and size of data associated with variables. For example:
int myVar;
Here, myVar is a variable of int (integer) type. The size of int is 4 bytes.
• Data types are used to define a variable before to use in a program.
• Size of variable, constant and array are determined by data types.

RANGE AND SIZE OF DIFFERENT DATA TYPES:

EXAMPLE OF DATA TYPE:
Input: Output:

OPERATOR:
 An operator is a symbol that tells the
computer to perform certain mathematical or
logical manipulations.
 These operators are used in programs to
manipulate data and variables.

TYPES OF OPERATOR:
• Arithmetic operators
• Relation operators
• Logical operators
• Assignment operators
• Increment and decrement operators
• Conditional operators
• Bitwise operators
• Special operators

ARITHMETIC OPERATORS:
 Arithmetic operator are used to perform numeric calculations
among the values.
Operators Meaning
+ Addition or unary plus
- Subtraction or unary minus
* Multiplication
/ Division
% Modulo division

EXAMPLE:
main()
{
int a,b,add,sub,mul,div,mod;
printf(“Enter two integer value:”);
scanf(“%d%d”,&a,&b);
add=a+b;
sub=a-b;
mul=a*b;
div=a/b;
mod=a%b;
Printf(“Summation=%d”,add);
Printf(“subtract=%d”,sub);
Printf(“Multiplication=%d”,mul);
Printf(“Division=%d”,div);
Printf(“Module=%d”,mod);
}
Enter two integer value:20 10
Summation=30
subtract=10
Multiplication=200
Division=2
Module=0
Output:

RELATION OPERATOR:
 Relational operators are used to compare two quantities and take certain decision depending
on their relation.
• If the relation is true it returns one.
• If the relation is false it returns zero.
Operator Meaning
< is less than
<= is less than or equal
> is greater then
>= is greater then or equal
== is equal to
!= is not equal to

EXAMPLE:
main()
{
int x=12,y=14,z=12;
printf("The number of X,Y,Zn");
//is x greater than y
printf("x>y=%dn",x>y);
//is z less than y
printf("x<y=%dn",x<y);
//is y greater than or equal z
printf("y>=z=%dn",y>z);
//is x equal y
printf("x==y=%dn",x==y);
//is y not equal to z
printf("y!=z=%d",y!=z);
}
The number of X,Y,Z
x>y=0
x<y=1
y>=z=1
x==y=0
y!=z=1
Output:

LOGICAL OPERATOR:
 Logical operator are used for testing more than one condition and making decisions.
Operator Meaning
&& Logical AND
|| Logical OR
! Logical NOT

EXAMPLE:
main()
{
int x=12,y=15,z=13,sum;
printf("Enter the numbers of X,Y,Zn");
//logical And
sum=(x!=z) && (x>y);
printf("(x!=z) && (x>y) is %dn",sum);
//logical Or
sum=(x>=y) || (y<z);
printf("(x>=y) || (y<z) is %dn",sum);
//Logical Not
sum=(x!=y);
printf("(x!=y) is %dn",sum);
}
Enter the numbers of X,Y,Z
(x!=z) && (x>y) is 0
(x>=y) || (y<z) is 0
(x!=y) is 1
Output:

ASSIGNMENT OPERATOR:
• These operator are used for assigning the result of an expression to a variable.
• b=a
Statement of simple assignment
operator
Statement with shorthand operator
a =a+1 a + = 1
a=a-1 a-=1
a=a*(n+1) a*=(n+1)
a=a/(n+1) a/=(n+1)
a=a%b a%=b

EXAMPLE:
main()
{
int a,b,c;
printf(“Enter three integer number:n”);
scanf(“%d%d%d”,&a,&b,&c);
printf(“value=%dn”,c+=b);
printf(“value=%dn”,c-=b);
printf(“value=%dn”,c*=b);
printf(“value=%dn”,c/=b);
printf(“value=%dn”,c%=b);
}
Output:
Enter three integer number:
5 10 15
value=25
value=15
value=150
value=15
value=5

INCREMENT AND DECREMENT OPERATORS:
C allows two very useful operators. These are the increment and decrement operators:
++ and --
• The operator ++ adds one to the operands.
• The operator – subtracts one from the operand.
**Both are unary operators and can be used as pre or post increment or decrement.

CSE 1201: Structured Programming Language

EXAMPLE:
main()
{
int a,b,c;
printf(“Enter three integer number:n”);
scanf(“%d%d%d”,&a,&b,&c);
printf(“value=%dn”,c=++a);
printf(“value=%dn”,c=a++);
printf(“value=%dn”,c=--a);
printf(“value=%dn”,c=a--);
}
Output:
Enter three integer
number:
4 5 6
value=5
value=5
value=5
value=5

CONDITIONAL OPERATORS:
Syntax:
exp1?exp2:exp3
Where exp1,exp2,exp3 are expressions.
Operator:
?: (ternary operator)
 These conditional operator are used to construct
conditional expressions of the form.

EXAMPLE:
main()
{
int num1,num2,result;
printf("Enter two numbers : n");
scanf("%d%d",&num1,&num2);
result=(num1>num2) ? num1 : num2;
printf("The maximum number between %d and %d is %dn",num1,num2,result);
}
Enter two numbers :
10
20
The maximum
number between 10
and 20 is 20
Output:

BITWISE OPERATORS:
• These operator works on bit level
• Applied to integer only.
operator Meaning
& Bitwise AND
| Bitwise OR
^ Bitwise exclusive OR
<< Shift left
>> Shift right

SPECIAL OPERATORS:
C supports some special operators such as-
• comma operator
• sizeof operator
• pointer operators comma
operator
sizeof
operator
pointer
operators

COMMA OPERATOR:
• The operator is used to combine related expressions.
• A comma linked list of expressions are evaluated left to right and the value of right
most expression is the value of combined expression.
Example:
value=(x=10,y=5,x+y);

SIZE OF OPERATOR:
Sizeof is an operator used to return the number of bytes the operand occupies.
Syntax:
m=sizeof(sum);
K=sizeof(2351);

DECISION MAKING STATEMENT:
• Also known as control structure
• Controls the flow of execution
• Execute program until a specific control is met
• One of the most important parts in programming

TYPES OF DECISION-MAKING STATEMENT:
If-else
If If-else If-else if Nested if
Switch

IF STATEMENT:
• The expression must be evaluating to true or false.
• The “Statement” can be a group or in braces.
• Syntax:
If (expression)
{
statement 1;
statement 2;
}

EXAMPLE:
main()
{
int n;
printf(“Enter any number:”);
scanf(“%d”,&n);
if(n>25)
{
printf(“You can marry now”);
}
}
Enter any number:
26
You can marry now
Output:

IF-ELSE STATEMENT:
• An extension version of if statement.
• Generally in the form of if (test expression)
• Syntax:
If (test expression)
{
true block statement
}
else
{
false block statement
}

EXAMPLE:
main()
{
int num1,num2;
printf("Enter any two number: n");
scanf("%d%d",&num1,&num2);
if(num1==num2)
{
printf("They are equal");
}
else
{
printf("They are not equal");
}
}
Enter any two number:
10 11
They are not equal
Output

IF-ELSE IF:
• It is used to give series of decision.
• Syntax:
If (condition)
{
Statement 1;
}
Else if (condition 2)
{
Statement 2;
}
Else
{
Statement when all condition are false.
}

EXAMPLE:
main()
{
int num;
printf("Enter integer numn");
scanf("%d",&num);
if(num>0)
{
printf("positive");
}
else if(num<0)
{
printf("Negative");
}
else if(num==0)
{
printf("Zero");
}
}
Enter integer number
1000000
positive
Output:

NESTED IF-ELSE STATEMENT:
• New block or if else statement defined in exiting if or else block statement.
• Syntax:
If(condition1)
{
if(condition2)
{
statement1;
}
else
{
Statement2;
}
}
else
{
Statement3;
}

SWITCH STATEMENT:
• Multi-way decision statement
• Tests the value of a given variable against a list of case values.
• When a match is found, a block of statements associated with that case is executed.
• Syntax:
switch(<selector expression>)
{
Case<value1>: <sequence of statements>;
break;
Case<value2>: <sequence of the
statements>;
break;
Case<value3>: <sequence of statements>;
break;
Default: <sequence of statements>;

EXAMPLE:
main()
{
int num;
printf("Enter any number :n");
scanf("%d",&num);
switch(num % 2)
{
case 0:
printf("This number is even number");
break;
case 1:
printf("This number is odd number");
break;
}
}
Enter any number:
10
This number is even number
Output:

LOOPS:
Loops are used in programming to repeat a specific block until some end
condition is met.
 There are three loops in c programming.
 for loop
 while loop
 do while loop

FOR LOOP:
• The syntax of a for loop is:
for(initialization ; condition; variable update)
{
//code to execute while the condition is true
statement;
}

EXAMPLE:
main()
{
int i;
for(i=1;i<=50;i++)
printf("%dn",i);
}
1234567891011121314151617181920
2122232425262728293031323334353
63738394041424344454647484950
Output:

WHILE LOOP:
• The syntax of a while loop is:
while(condition)
{
//body of the loop
statement;
variable update;
}

EXAMPLE:
main()
{
int i;
i=1;
while(i<=5)
{
printf(“NDUBn");
i++;
}
}
NDUB
NDUB
NDUB
NDUB
NDUB
Output:

DO WHILE LOOP:
• The syntax of a do while loop is:
do
{
//body of the loop
Statement;
variable update;
}
While (condition);

EXAMPLE:
main()
{
int i,s=0;
i=1;
do
{
if(i%2!=0)
s=s+i;
i++;
}
while(i<=10);
printf("Summation of ODD numbers: %dn",s);
}
Summation of ODD numbers: 25
Output:

BREAK STATEMENT:
• The break statement terminates the loop immediately when it is
encountered.
• The break is used with decision making statement such as if else
• Syntax of the break statement:
break;

EXAMPLE:
int main()
{
int num;
for (num =100; num>=10; num --)
{
printf(“num: %dn", num);
if (num==99)
{
break;
}
}
printf("Out of for-loop");
}
num: 100
num: 99
Out of for-loop
Output:

CONTINUE STATEMENT:
• The continue statement skips some statements inside loop.
• The continue statement is used with decision making statement such as if
else.
• Syntax of continue statements:
continue;

EXAMPLE:
int main()
{
int j=0;
do
{
if (j==7)
{
j++;
continue;
}
printf("%d ", j);
j++;
}
while(j<10);
}
0 1 2 3 4 5 6 8 9
Output:

CSE 1201: Structured Programming Language

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