CS201- Introduction to Programming- Lecture 05
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Transcript of CS201- Introduction to Programming- Lecture 05
Introduction to ProgrammingIntroduction to Programming
Lecture 5Lecture 5
In the Previous In the Previous LectureLecture
Basic structure of C programBasic structure of C program Variables and Data typesVariables and Data types OperatorsOperators ‘ ‘cout’ and ‘cin’ for output and inputcout’ and ‘cin’ for output and input BracesBraces
DecisionDecision
If StatementIf StatementI f condition is trueIf condition is true
statementsstatements
If Ali ’s height is greater then 6 If Ali ’s height is greater then 6 feetfeet
Then Then Ali can become a member of the Ali can become a member of the Basket Ball teamBasket Ball team
If Statement in If Statement in CC
If (condit ion)If (condit ion)statement ;statement ;
If Statement in If Statement in CC
I f ( condit ion )If ( condit ion ){{
statement1 ;statement1 ;statement2 ;statement2 ;
::} }
I f statement in CIf statement in C
i f (age1 > age2)if (age1 > age2)cout<<“Student 1 is older cout<<“Student 1 is older than student 2” ;than student 2” ;
Relational Relational OperatorsOperators
< < less thanless than<= <= less than or equal toless than or equal to== equal to== equal to>= greater than or equal to>= greater than or equal to> greater than> greater than!= not equal to!= not equal to
Relational Relational OperatorsOperators
a != b;a != b;
X = 0;X = 0;X == 0;X == 0;
ExampleExample#include <iostream.h>#include <iostream.h>main ( ) main ( ) {{
int AmirAge, AmaraAge;int AmirAge, AmaraAge;AmirAge = 0;AmirAge = 0;AmaraAge = 0;AmaraAge = 0;
cout<<“Please enter Amir’s age”;cout<<“Please enter Amir’s age”;cin >> AmirAge;cin >> AmirAge;cout<<“Please enter Amara’s age”;cout<<“Please enter Amara’s age”;cin >> AmaraAge;cin >> AmaraAge;
if AmirAge > AmaraAge) if AmirAge > AmaraAge) {{
cout << “\n”<< “Amir’s age is greater then Amara’s age” ;cout << “\n”<< “Amir’s age is greater then Amara’s age” ;} }
}}
Flow Chart SymbolsFlow Chart SymbolsStart or stop
Process
Continuation mark
Decision
Flow line
Flow Chart for i f statementFlow Chart for i f statement
Condition
Process
IF
Then
Entry point for IF block
Exit point for IF block
Note indentation from left to right
ExampleExampleIf the student age is greater than 18 If the student age is greater than 18
or his height is greater than five or his height is greater than five feet then put him on the foot balll feet then put him on the foot balll teamteam
ElseElsePut him on the chess teamPut him on the chess team
Logical OperatorsLogical Operators
ANDAND &&&&OROR ||||
Logical OperatorsLogical OperatorsIf a is greater than b If a is greater than b
AND c is greater than dAND c is greater than d
In Cif(a > b && c> d)if(age > 18 || height > 5)
i f-elseif-elseif (condition)if (condition){{
statement ;statement ;----
}}elseelse{{
statement ;statement ;----
}}
i f-elseif-elseCondition
Process 1
IF
Then
Entry point for IF-Else block
Exit point for IF block
Process 2
Else
Note indentation from left to right
Code
if (AmirAge > AmaraAge) { cout<< “Amir is older than Amara” ;}
if (AmirAge < AmaraAge) { cout<< “Amir is younger than Amara” ;}
Example Example
ExampleExampleCodeCode
if AmirAge > AmaraAge) if AmirAge > AmaraAge) {{ cout<< “Amir is older than Amara” ;cout<< “Amir is older than Amara” ;} } else else {{ cout<<“Amir is younger than Amara” ;cout<<“Amir is younger than Amara” ;}}
Make a small f low chart of thisMake a small f low chart of thisprogram and see the one to program and see the one to
oneonecorrespondence of the chart correspondence of the chart and the codeand the code
Example Example CodeCode
if AmirAge > AmaraAge) if AmirAge > AmaraAge) {{ cout<< “Amir is older than Amara” ;cout<< “Amir is older than Amara” ;} } else else {{ cout<<“Amir is younger than or of the same age cout<<“Amir is younger than or of the same age
as Amara” ;as Amara” ;}}
ExampleExampleIf (AmirAge != AmaraAge)If (AmirAge != AmaraAge) cout << “Amir and Amara’s Ages cout << “Amir and Amara’s Ages
are not equal”;are not equal”;
Unary Not operator Unary Not operator !!
!true = false!true = false !false = true!false = true
If (!(AmirAge > AmaraAge))If (!(AmirAge > AmaraAge))
??
ExampleExample
i f (( interMarks > 45) && (testMarks >= passMarks))i f (( interMarks > 45) && (testMarks >= passMarks)){ {
cout << “ Welcome to Virtual University”;cout << “ Welcome to Virtual University”;} }
ExampleExample
If(!((interMarks > 45) && (testMarks >= passMarks)))If(!((interMarks > 45) && (testMarks >= passMarks)))
??
Nested ifNested ifI f (age > 18)If (age > 18){{
If(height > 5)If(height > 5){{
::}}
}}Make a f lowchart of this nested if Make a f lowchart of this nested if
structure…structure…
In Today’s Lecture In Today’s Lecture DecisionDecision
– IfIf– ElseElse
Flowcharts Flowcharts Nested if Nested if