← if / else: app rules lesson New set →

App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 301 · 40 questions
TalentJR

Developer's tip (Test, then choose): if (test) { A } else { B }: A runs when the test is true, B when it is false. else if: check from the top; the first true test wins and the rest are skipped. >= includes the number itself; > does not. === tests “is equal to”.

NameDateTime takenScore ___ / 40
  1. 1.🔀 What does this sign-up rule show?
    let age = 11;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  2. 2.🔀 What number does this shop app show?
    let total = 440;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  3. 3.🔀 What does this battery rule show?
    let battery = 35;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  4. 4.🔀 What does this sign-up rule show?
    let age = 14;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  5. 5.🔀 What does this PIN rule show?
    let pin = "7175";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  6. 6.🔀 Which badge does this quiz app show?
    let marks = 44;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  7. 7.🔀 What does if / else let an app do? (a) pick one of two actions (b) save a photo (c) repeat forever (d) draw a screen
  8. 8.🔀 What does this PIN rule show?
    let pin = "408";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  9. 9.🔀 What does this PIN rule show?
    let pin = "1806";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  10. 10.🔀 With if / else if / else, how many parts run? (a) two (b) none (c) all of them (d) only one
  11. 11.🔀 What does this battery rule show?
    let battery = 6;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  12. 12.🔀 What does this sign-up rule show?
    let age = 17;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  13. 13.🔀 What does this sign-up rule show?
    let age = 10;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  14. 14.🔀 What does >= mean? (a) smaller or equal (b) greater than or equal (c) not equal (d) less than
  15. 15.🔀 What does this PIN rule show?
    let pin = "3055";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  16. 16.🔀 What does this sign-up rule show?
    let age = 8;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  17. 17.🔀 What does this PIN rule show?
    let pin = "7886";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  18. 18.🔀 Which badge does this quiz app show?
    let marks = 47;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Bronze (c) Gold
  19. 19.🔀 In this course’s code, which sign tests “is equal to”? (a) => (b) === (c) = (d) !==
  20. 20.🔀 When does the else part run? (a) when the test is true (b) always (c) when the test is false (d) never
  21. 21.🔀 What does this battery rule show?
    let battery = 36;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  22. 22.🔀 Which badge does this quiz app show?
    let marks = 80;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  23. 23.🔀 Which badge does this quiz app show?
    let marks = 59;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  24. 24.🔀 What does this PIN rule show?
    let pin = "132";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  25. 25.🔀 What does this sign-up rule show?
    let age = 13;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  26. 26.🔀 What does this battery rule show?
    let battery = 13;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  27. 27.🔀 What does this PIN rule show?
    let pin = "12949";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  28. 28.🔀 What does this PIN rule show?
    let pin = "6716";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  29. 29.🔀 What number does this shop app show?
    let total = 780;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  30. 30.🔀 What does this sign-up rule show?
    let age = 15;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  31. 31.🔀 What does this PIN rule show?
    let pin = "4872";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  32. 32.🔀 What does this PIN rule show?
    let pin = "93268";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  33. 33.🔀 What does this PIN rule show?
    let pin = "98149";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  34. 34.🔀 What number does this shop app show?
    let total = 640;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  35. 35.🔀 What does this PIN rule show?
    let pin = "4844";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  36. 36.🔀 What does this battery rule show?
    let battery = 99;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  37. 37.🔀 What number does this shop app show?
    let total = 290;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  38. 38.🔀 What number does this shop app show?
    let total = 820;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  39. 39.🔀 What does this PIN rule show?
    let pin = "97063";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  40. 40.🔀 What number does this shop app show?
    let total = 710;
    if (total > 500) {
      total = total - 50;
    }
    show(total);

Answer key

  1. Ask a parent
  2. 440
  3. Battery OK
  4. Welcome!
  5. PIN saved
  6. Bronze
  7. pick one of two actions
  8. Use 4 digits
  9. PIN saved
  10. only one
  11. Low battery
  12. Welcome!
  13. Ask a parent
  14. greater than or equal
  15. PIN saved
  16. Ask a parent
  17. PIN saved
  18. Bronze
  19. ===
  20. when the test is false
  21. Battery OK
  22. Gold
  23. Silver
  24. Use 4 digits
  25. Welcome!
  26. Low battery
  27. Use 4 digits
  28. PIN saved
  29. 730
  30. Welcome!
  31. PIN saved
  32. Use 4 digits
  33. Use 4 digits
  34. 590
  35. PIN saved
  36. Battery OK
  37. 290
  38. 770
  39. Use 4 digits
  40. 660

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