Dev Blog

Summary ​

Conclusions ​

Control flow constructs change a program's sequential execution order. if/else and the ternary operator ?: choose an action based on a Boolean condition; the switch statement and expression select by values and patterns: constant, relational, and logical (and, or, not). A switch expression returns a value and must be exhaustive. A while loop checks its condition before an iteration, while do/while checks afterward and runs the body at least once; for is convenient for counters, and foreach for iterating over collection elements. break and continue control loop execution, and most tasks can be solved with common algorithms: accumulating a sum, counting, finding minimum and maximum values, and approximate calculations with a specified accuracy.

Self-check questions ​

  1. What is a code block? What is the scope of a variable declared inside it?
  2. How does an else if chain work? Why does condition order matter?
  3. What happens if you place a semicolon after an if condition?
  4. How does the ternary operator ?: differ from an if statement?
  5. How does a switch statement work? Why is there no fall-through between branches in C#?
  6. Which patterns can you use with is and in a switch expression?
  7. What is the purpose of a when condition in a case branch?
  8. How does a switch expression differ from a switch statement? What does an exhaustive expression mean?
  9. How does while differ from do/while? Give examples of their use.
  10. What are the parts of a for loop header? In what order are they executed?
  11. How many times is the inner loop body executed in nested loops?
  12. What is foreach for? Can you modify its iteration variable?
  13. How do break, continue, and return differ?
  14. How can you exit multiple nested loops at once?
  15. How can you use a loop to calculate a value to a specified accuracy?