Lecture No. 3

Bilal Ashfaq Ahmed

TaskCalculate the average age of a class of ten

students. Prompt the user to enter the age of each student.

#include <iostream.h>#include<conio.h>void main ( ){

int age1, age2, age3, age4, age5, age6, age7, age8, age9, age10 ;int TotalAge ;

int AverageAge ;

cout << “ Enter the age of student 1: “ ;cin >> age1 ;

cout << “ Enter the age of student 2: “ ;cin >> age2 ;::TotalAge = age1+ age2 + age3+ age4+ age5+age6+ age7+ age8+age9 + age10 ;

AverageAge = TotalAge / 10 ;

cout<< “The average age of the class is :” << AverageAge ;

getch();}

Quadratic EquationIn algebra

y = ax2 + bx + cIn C++

y = a*x*x + b*x + c

a*b%c +d

Rule of EvaluationIn algebra, there may be curly brackets { } and square brackets

[ ] in an expression but in C we have only parentheses ( ). Using parentheses, we can make a complex expression easy to read and understand and can force the order of evaluation. We have to be very careful while using parentheses, as parentheses at wrong place can cause an incorrect result.

No expression on the left hand side of the assignmentInteger division truncates fractional partLiberal use of brackets/parenthesis

Interesting ProblemWrite a program that accepts Four digit number from

the user decomposes it into first, second, third and four digit .

For example if number =1234 then

first=1

Second=2

Third=3

Fourth=4

/* A program that takes a four digits integer from user and shows the digits on the screen

separately i.e. if user enters 1234, it displays 1,2,3,4 separately. */

#include <iostream.h>#include<conio.h>void main (){// declare variables

int num;int fd, sd, td, frd;clrscr();

// prompt the user for inputcout <<"\n\t Enter the Four Digit Number: ";cin >> num;

// Seperation logic

fd = num / 1000;sd = (num % 1000)/100;td = (num % 100)/10;frd= num % 10;

// Display number seperately

cout<<"\n\t First Digit: "<<fd;cout<<"\n\t Second Digit: "<<sd;cout<<"\n\t Third Digit: "<<td;cout<<"\n\t Fourth Digit: "<<frd;

getch();}

TaskWrite a program that takes radius of a circle

from the user and calculates the diameter, circumference and area of the circle and display the result.