The document provides 5 examples of C++ code demonstrating the use of loops, including a while loop to output text a number of times based on user input, a for loop within a class to calculate mortgage payments over the life of a loan, a for loop that sums all numbers from 0 to a user-input number, and an infinite for loop that continuously outputs text. Each example is presented with its code, expected output, and screenshots of sample runs to illustrate the loop functionality.
1. Loop example 1
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#include <iostream>
using namespace std;
int main()
{
int counter = 0; // Initialize counter to 0.
int numTimes = 0; // Variable for user to enter the amount of times.
cout << "How many times do you want to see Einstein?: ";
cin >> numTimes; // This is how many times the loop repeats.
cout << "n";
while (counter < numTimes) // Counter is less than the users input.
{
cout << "Einstein!n";
counter++; // Increment the counter for each loop.
}
cout << "n";
return 0;
}
2. Screenshot
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/
*===============================[outpu
t]====================================
How many times do you want to see
Einstein?: 6 Einstein! Einstein! Einstein!
Einstein! Einstein! Einstein! Press any key to
continue . . .
=====================================
=====================================
===*/
3. Loop Example 2
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#include "math.h"
#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
using std::cout;
using std::endl;
using std::cin;
//mortgage class//
class Mortgage
{
public:
void header();
void enterprinc();
double princ;
double anInt;
int yrs;
};
//define function//
void Mortgage::header()
{
cout << "Welcome to Smith's Amortization Calculatornn";
cout << endl;
cout << "Week 3 Individual Assignment C++ Mortgage Amortization Calculatornn";
cout << endl;
}
void Mortgage::enterprinc()
{
cout << endl;
cout << "Enter the amount The Mortgage Amount:$";
cin >> princ;
}
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//main function//
int main ()
{
Mortgage mortgageTotal;
double princ = 0;
double anInt [4]= {0, 5.35, 5.5, 5.75,};
double yrs [4]= {0, 7, 15, 30,};
double pmt = 0;
double intPd = 0;
double bal = 0;
double amtPd = 0;
double check(int min, int max);
int NOP = 0;
int Mnth = 0;
int SL = 0;
char indicator = ('A' ,'a','R','r','D','d');
int select;
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//Begin Loop
{
mortgageTotal.header ();
mortgageTotal.enterprinc ();
cout<< "Please Enter Your Selection!"<< endl;
cout<< "Press A to make selection for term of mortgage and interest rate"<<endl;
cin >> indicator;
if (indicator == 'A','a')
{
cout << "Please select your Terms and Rates from the following choices: " <<
endl;
cout << "1. 7 years at 5.35%" << endl;
cout << "2. 15 years at 5.5%" << endl;
cout << "3. 30 years at 5.75%" << endl;
cout << endl;
cout << "What is your selection:";
select = 0;
cin >> select;
cout << endl << endl << endl;
switch (select)
{
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case 0: cout << endl;
break;
case 1:
yrs[2] = 7;
anInt[2] = 5.35;
cout << "You have selected a 7 year mortgage at 5.35% interest." << endl;
break;
case 2:
yrs[3] = 15;
anInt[3]= 5.50;
cout << "You have selected 15 year mortgage at 5.50 interest%" << endl;
break;
case 3:
yrs[4] = 30;
anInt[4] = 5.75;
cout << "You have selected a 30 year mortgage at 5.75% interest" << endl;
break;
default:
cout << "Invalid Line Number" << endl;
if ((select < 1)|| (select > 3))
{
system("cls");
cout << "Your choice is invalid, please enter a valid choice!!!";
system("PAUSE");
system("cls");
return main();
}
}
}
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//Formulas//
double pmt = (mortgageTotal.princ*((anInt[select]/1200)/(1 - pow((1+(anInt[select]/1200)),-1*(yrs[select]*12))))); // notice the variable in the brackets
that i added.
cout << "Your Monthly Payment is: $" << pmt << "n";
cout << endl;
double NOP = yrs [select] * 12;
SL = 0;
for (Mnth = 1; Mnth <= NOP; ++Mnth)
{
intPd = mortgageTotal.princ * (anInt[select] / 1200);
amtPd = pmt - intPd;
bal = mortgageTotal.princ - amtPd;
if (bal < 0)bal = 0;
mortgageTotal.princ = bal;
if (SL == 0)
{
cout << "Balance of Loan" << "tttAmount of Interest Paid" << endl;
}
cout << setprecision(2) << fixed << "$" << setw(5) << bal << "tttt$"<< setw(5) << intPd << endl;
++SL;
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//Allows user to decide whether or not to continue//
if (SL == 12)
{
cout << "Would you like to continue the amoritization or quit the program?n";
cout << endl;
cout << "Enter 'R' to see the remainder or 'D' for done.n";
cin >> indicator;
if
(indicator == 'R','r')SL = 0;
else
if
(indicator == 'D','d')
cout << endl;
}
}
}
return 0;
}
9. Loop example 3
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#include <iostream>
using namespace std;
int main()
{
int number = 0; // Variable for user to enter a number.
int sum = 0; // To hold the running sum during all loop iterations.
cout << "Enter a number: ";
cin >> number;
// Loop keeps adding until it reaches the number entered.
for (int index = 0; index <= number; index++)
{
sum += index; // Each iteration Adds to the variable sum.
}
// cout statement is put after the loop.
cout << "nThe sum of all numbers from 0 to " << number
<< " equals: " << sum << "nn";
return 0;
}
10. Screenshot
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*===========================[output]====
=============================== Enter a
number: 6 The sum of all numbers from 0 to
6 equals: 21 Press any key to continue . . .
=====================================
===================================*/
11. Loop example 4
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#include <iostream>
using namespace std;
int main()
{
char selection;
cout<<"n Menu";
cout<<"n========";
cout<<"n A - Append";
cout<<"n M - Modify";
cout<<"n D - Delete";
cout<<"n X - Exit";
cout<<"n Enter selection: ";
cin>>selection;
switch(selection)
{
case 'A' : {cout<<"n To append a recordn";}
break;
case 'M' : {cout<<"n To modify a record";}
break;
case 'D' : {cout<<"n To delete a record";}
break;
case 'X' : {cout<<"n To exit the menu";}
break;
// other than A, M, D and X...
default : cout<<"n Invalid selection";
// no break in the default case
}
cout<<"n";
return 0;
}
13. Loop Example 5
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#include <iostream>
using namespace std;
int main ()
{
for( ; ; )
{
printf("This loop will run forever.n");
}
return 0;
}