CSC 1060 Week 07: Control Structures

Course Information

• Course name: CSC 1060
• Topic: Control Structures: Repetition
• Week: 07

Objectives

• Write programs with repeated statements using while or do-while loops.
• Control loops using user input, confirmation, and sentinel values.
• Understand similarities and differences of for, for range-based, while, while counting, while sentinel, and do-while loops.
• Implement program control using break and continue statements.

Agenda

• Loop definitions
• Types of Loops
• for, for range-based loops
• while counting loops, sentinel loops
• do...while loops
• break and continue statements
• while flag-controlled loops
• Additional resources/help

Loop Definitions

• Loops repeat a sequence of instructions until a condition is met.
• Avoid using goto statements for loops.
• Loop iteration: repeated code block
• Number of iterations: How many times the loop runs.
• Loop test expression: Controls how the loop runs.
• Terminating loop: A loop that stops repeating. Every loop needs a way to terminate.

Control Structure: Repetition

• Loops involve an initialization value.
• The condition to continue is evaluated.
• If the condition is true, execute the code.
• Update the initialization value.

For Counting Loop

• The counter variable can be declared inside the loop for block scope.
• A counter variable (e.g., i) is common.
• The loop format: for(initialize test update) {body of code to repeat}

For Range-Based Loop

• Iterates over all elements in a range (sequence)
• The declaration creates a block scope variable to hold each element in the range.
• The loop format: for(declaration: range) {body to repeat}

While Counting Loop

• Example: int i=0; while(i < num){body to repeat; i++}
• Initialization expression (int i=0)
• Test condition (i < num)
• Code inside the loop (body to repeat)
• Update expression (i++)

While Sentinel Loop

• A sentinel value is used to terminate the loop.
• The loop might not run.
• Example: while (ans != 'Q') {get input, do work}

Do...While Loop

• Executes the code block at least once
• The while condition is checked after executing the code block
• Format: do {body to repeat} while (test condition)

Break Statement

• Terminates the loop when a condition is true
• Used in for, while, and do-while loops
• Format (general example): if (condition) { break; }

Continue Statement

• Skips the current iteration of the loop
• Control moves to the next iteration
• continue is used in for, while, and do-while loops
• Format (general example): if (condition) { continue; }

Flag-Controlled Loop

• Uses a Boolean flag to control the loop
• The loop runs until the flag is set to true
• The loop checks the flag before running again.

Review Exercises

• Complete Parsons exercises.
• Work through problems 1-10 in thinkcpp(pick minimum 3)

Pre-work Grade

• Post discussion and research solutions to D2L.
• Complete Week 07 Content Module in D2L (100%).

Help/Questions

• Student office hours (by appointment and drop-in)
• Email: [email protected]
• RRCC On-Campus Tutoring: https://www.rrcc.edu/learning-commons/tutoring
• 24/7 Online Tutoring: D2L > Content > Resources for Help

This quiz covers the topic of control structures, specifically focusing on repetition using loops in programming. It explores various types of loops such as while, do-while, and for loops, including their control mechanisms and differences. Prepare to showcase your understanding of loop implementation and control statements.