CSCI 102 – Lab 06

Week 6 Lab

Q&A on Material

Defining and calling simple functions
While loops

Exercises

Walk through these exercises and complete them as a group (if time allows).

Function Tracing

#include <iostream>
using namespace std;
double withdraw(double balance, double amount);
double deposit(double balance, double amount);
bool isOverdrawn(double balance);

int main()
{
    double balance = 100.0;
  
    // deposit two paychecks and try to withdraw 
    balance = deposit(balance, 500.0);
    if ( !isOverdrawn(withdraw(deposit(balance, 700.0), 400.0)) )
    {
         balance = withdraw(deposit(balance, 700.0), 400.0); 
    }
    return 0;
}
double withdraw(double balance, double amount) {
    balance -= amount;
    return balance;
}
double deposit(double balance, double amount) {
    balance += amount;
    return balance;
}
bool isOverdrawn(double balance) {
    return balance < 0.0;
}

Solution

While Loop Tracing

Determine the output of this program by tracing its execution manually.

#include <iostream>
#include <string>
using namespace std;

int main()
{
  int x = 0;
  int y = 1;
  while (!((x % 5 == 0) && (y % 64 == 0)))
  {
    x++;
    y *= 2; 
  }
  cout << x << " " << y << endl;
  return 0;
}

Solution

Function Coding

cpp/cs102/lab6/polygon-area

cpp/cs102/lab6/isosceles

Loop Exercises

Walk through these exercises and complete them as a group (if time allows).

cpp/cs102/practice7/whileMC1

cpp/cs102/practice7/nextOdd

cpp/while/div-without-div

cpp/cs102/practice7/sumDigits

HW help

Q&A regarding the current homework.

Want to Learn More (Individual Study)

Coding Practices

We hope that as you learn the basics of programming you can also start to learn good coding practices to make your code more readable and well-organized. Below are some helpful links to improving your coding of conditionals that also involve functions. Take some time to read over them and see if you can improve any of your code either from last week’s or this week’s lab.

Take a look at the idioms related to basic loop (iterative) statements:

Open-ended Help

Any students with questions may stay after to get help. Please ask questions! Anyone else may leave at this stage.