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Programming Fundamentals. Lecture 5. In the Previous Lecture. Basic structure of C program Variables and Data types Operators ‘ cout ’ and ‘ cin ’ for output and input Braces. Relational Operators. Decision. If Statement. If condition is true statements - PowerPoint PPT Presentation
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Programming Fundamentals
Lecture 5
In the Previous Lecture
• Basic structure of C program• Variables and Data types• Operators• ‘cout’ and ‘cin’ for output and input• Braces
Relational Operators
Decision
If Statement
If condition is truestatements
If Ali’s height is greater then 6 feetThen
Ali can become a member of the Basket Ball team
If Statement in C
If (condition)statement ;
If Statement in C
If ( condition ){
statement1 ;statement2 ;
:}
If statement in C
• Int n;• Cin>>n;• If(n>10)• {
• Cout<<“uol”;• Cout<<“ok”;
• }
Add two num..r they equal to five??
Divisible by 3
• Int n;• Cout<<“enter any number”;• Cin>>;• If(n%3==0)• {
• Cout<<“the number”<<n<<“is divisible by 3”;
• }
If-else statement
• Used for making two way decsns(need?)• One condition and two blocks of statements are given• After evaluating a condition, one of the block will be executed• If condition is true than the first block will be executed• If condition is false than the second block will be executed
if-elseif (condition){
statement ;--
}else{
statement ;--
}
<100 or >100
• Int n;• Cout<<“enter any integer value”;• Cin>>n;• If(n>100)• Cout<<“>100”;• Else• Cout<<“<100”;
Even or odd
• Int n;• Cout<<“enter an integer”;• Cin>>n;• If(n%2==1)• Cout<<“it is an odd number”;• Else• Cout<<“even”;
Take avg of 5 students marks and tell if that avg is > or < 100
Nested if statement
When an if statement is used within another if statement , it is called nested if statement
Used for multiway (not two way) decision making
Syntax
If(condition-1){
If (condition-2){
Statement}Statement
}
example
Int a,b,c;CoutCin>>aCoutCin>>b;CoutCin>>c;If(a==b){
if(a==c)cout<<“equal”;
}ElseCout<<“different”;}
Nested if-else structure
Used for multiple selectionSyntaxIf(condition1)Statement1;Else if(condition2)Statement2;Else if(condition3)Statement3…....
Logical Operators
AND &&OR ||
Logical OperatorsIf a is greater than b
AND c is greater than d
In Cif(a > b && c> d)if(age > 18 || height > 5)
Multi-way decision
if ( grade ==‘A’ )cout << “ Excellent ” ;
if ( grade ==‘B’ )cout << “ Very Good ” ;
if ( grade ==‘C’ )cout << “ Good ” ;
if ( grade ==‘D’ )cout << “ Poor ” ;
if ( grade ==‘F’ )cout << “ Fail ” ;
if Statements
if ( grade ==‘A’ )cout << “ Excellent ” ;
else if ( grade ==‘B’ )
cout << “ Very Good ” ;else
if ( grade ==‘C’ )cout << “ Good ” ;
elseif ( grade ==‘D’ )
cout << “ Poor ” ;
if else
if ( grade == ‘A’ )cout << “ Excellent ” ;
else if ( grade == ‘B’ )…
else if ……
else …
if else
switch statement
switch statements
switch ( variable name ){
case ‘a’ :statements;
case ‘b’ :statements;
case ‘c’ : statements;
…}
switch ( grade){
case ‘A’ :cout << “ Excellent ” ;
case ‘B’ :cout << “ Very Good ” ;
case ‘C’ :…
…}
switch statements
case ‘A’ :cout << “ Excellent ” ;……
switch statements
Example
switch ( grade){
case ‘A’ :cout << “ Excellent ” ;
case ‘B’ :cout << “ Very Good ” ;
case ‘C’ :cout << “Good ” ;
case ‘D’ :cout << “ Poor ” ;
case ‘F’ :cout << “ Fail ” ;
}
break;
Exampleswitch ( grade ){
case ‘A’ :cout << “ Excellent ” ;break ;
case ‘B’ :cout << “ Very Good ” ; break ;
case ‘C’ :cout << “Good ” ; break ;
case ‘D’ :cout << “ Poor ” ; break ;
case ‘F’ :cout << “ Fail ” ; break ;
}
default :cout << “ Please Enter Grade from ‘A’ to ‘D’ or ‘F’ “ ;
default :
GOTO
{Int c=1;abc:Cout<<c<<endl;C++;If(c<=10)Goto abc;}
switch (grade)
Display “Excellent”
case ‘B’ :
case ‘A’ :
Display “Very Good”
Default :
“……..”
Flow Chart of switch statement
…
Limitations of switch
if ( amount > 2335.09 ) statements ;
Whole Number
• short• int• long
case ‘A’ :case ‘ 300 ‘ :case ‘ f ‘ :
if (c == ‘z’ )
{
cout << “ Great ! You have made the correct guess “ ;break ;
}
break ;
continue ;
continuewhile trynum <= 5 ;{
….….continue ;
}
for ( counter = 0 ;counter <= 10 ; counter ++ ){
…….continue ;
}
continue in ‘for’ loop
gotoUnconditional Branch of Execution
• Minimize the use of break• Minimize the use of continue• Never use goto
Flow Charting
• There are different techniques that are used to analyse and design a program. We will use the flow chart technique.
• A flow chart is a pictorial representation of a program.
• There are labelled geometrical symbols, together with the arrows connecting one symbol with other.
Flow Chart Symbols
Start or stop
Process
Flow line
Continuation mark
Decision
Unary Not operator !
!true = false !false = true
