Programming Fundamentals Lecture 4

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 If Ali’s height is greater then 6 feet Then 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-else if (condition) { statement ; - } else { statement ; - }

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; Cout Cin>>a Cout Cin>>b; Cout Cin>>c; If(a==b) { if(a==c) cout<<“equal”; } Else Cout<<“different”; }

Nested if-else structure Used for multiple selection Syntax If(condition1) Statement1; Else if(condition2) Statement2; Else if(condition3) Statement3…....

Logical Operators AND&& OR||

Logical Operators If a is greater than b AND c is greater than d In C if(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 ” ; else if ( 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;

Example switch ( 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 Unconditional Branch of Execution

GOTO { Int c=1; abc: Cout<<c<<endl; C++; If(c<=10) Goto abc; }

Limitations of switch if ( amount > ) statements ;

Whole Number short int long

case ‘A’ : case ‘ 300 ‘ : case ‘ f ‘ :

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