1. CS150 Introduction to Computer Science 1
More on Loops
So far, we’ve learnt about ‘while’ loops.
Today will learn about ‘for’ loops.
2/21/2019
CS150 Introduction to Computer Science 1

2. CS150 Introduction to Computer Science 1
For loops
3 main things for loops:
Initialization of lcv, testing of lcv, updating lcv
For loops provide a concise way to do this
for (count = 0; count < 5; count++)
cout << count << endl;
2/21/2019
CS150 Introduction to Computer Science 1

3. CS150 Introduction to Computer Science 1
General Format
for (initialization expression; loop repetition condition; update expression) {
statements; }
2/21/2019
CS150 Introduction to Computer Science 1

4. CS150 Introduction to Computer Science 1
Examples
Write a for loop that outputs odd numbers less than 10
Write a program that computes the factorial of a number
2/21/2019
CS150 Introduction to Computer Science 1

5. Localized Declarations
for (int i = 0; i < n; i++)
cout << i << endl;
i is declared ONLY in the loop
2/21/2019
CS150 Introduction to Computer Science 1

6. Rewrite using a while loop
for (i = 5; i < 10; i+= 2)
cout << i;
What does this output?
2/21/2019
CS150 Introduction to Computer Science 1

7. CS150 Introduction to Computer Science 1
Formatting Output
How can we generate this output?
Fahrenheit Celsius
2/21/2019
CS150 Introduction to Computer Science 1

8. CS150 Introduction to Computer Science 1
The Program
float F,C;
F = 32.0;
cout << fixed << setprecision(3);
cout << "Fahrenheit ";
cout << "Celsius" << endl;
while (F <= 212.0) {
C = (5.0/9.0)*(F - 32);
cout << setw(10) << F << setw(12) << C << endl;
F += 1; }
You must have #include<iomanip>
2/21/2019
CS150 Introduction to Computer Science 1

9. CS150 Introduction to Computer Science 1
Programs
Write a program that will print the sum of the odd integers between 1 and 50 inclusive. Write one program using a while and the other using a for loop.
2/21/2019
CS150 Introduction to Computer Science 1

10. CS150 Introduction to Computer Science 1
Program
Write a program that inputs 50 numbers and outputs the largest and the smallest number
2/21/2019
CS150 Introduction to Computer Science 1

11. CS150 Introduction to Computer Science 1
Conditional Loops
Loops that execute until some condition is met
Includes more than counting
Use while loops
2/21/2019
CS150 Introduction to Computer Science 1

12. CS150 Introduction to Computer Science 1
Program
Write a flag controlled loop that continues to read pairs of integers until it reads a pair with the property that the first integer is evenly divisible by the second
2/21/2019
CS150 Introduction to Computer Science 1