1. CS 1400 Chapter 5, section 2

2. Loops! while (rel-expression)while (rel-expression) {statements statement } if the relational-expression is true, execute the statement(s) then repeat. (This is a pre-test loop)

3. Example Convert a list of temperatures from Fahrenheit to Centigrade. int main() { float fahr; char continue = ‘Y’; while (continue == ‘Y’) { cout << “Enter a temperature: “; cin >> fahr; cent = 5.0/9.0 * (fahr-32.0); cout >> “centrigrade conversion is: “ << cent << endl; cout >> “Enter Y to continue…”; cin >> continue; }

4. Counting loops int main() { float fahr; int count = 0; while (count < 5) { cout << “Enter a temperature: “; cin >> fahr; cent = 5.0/9.0 * (fahr-32.0); cout >> “centrigrade conversion is: “ << cent << endl; count = count + 1; } Convert exactly 5 temperatures to centigrade…

5. Examples… Write a program to output the sum of a list of positive numbers provided by the user. Modify the above program to output the average of a list of positive numbers provided by the user. Write a program that prompts the user to enter an age in the range 18 to 25. Re- prompt the user if an invalid age is entered.