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App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 875 · 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 PIN rule show?
    let pin = "524";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  2. 2.🔀 Which badge does this quiz app show?
    let marks = 73;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  3. 3.🔀 What does if / else let an app do? (a) pick one of two actions (b) repeat forever (c) save a photo (d) draw a screen
  4. 4.🔀 What does this battery rule show?
    let battery = 33;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  5. 5.🔀 What does this battery rule show?
    let battery = 48;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  6. 6.🔀 What does this PIN rule show?
    let pin = "23030";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  7. 7.🔀 Which badge does this quiz app show?
    let marks = 90;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Bronze (c) Gold
  8. 8.🔀 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
  9. 9.🔀 What number does this shop app show?
    let total = 600;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  10. 10.🔀 What does this battery rule show?
    let battery = 16;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  11. 11.🔀 What does this battery rule show?
    let battery = 90;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  12. 12.🔀 What does this battery rule show?
    let battery = 87;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  13. 13.🔀 What does this battery rule show?
    let battery = 71;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  14. 14.🔀 What does this battery rule show?
    let battery = 63;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  15. 15.🔀 Which badge does this quiz app show?
    let marks = 82;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Bronze (c) Gold
  16. 16.🔀 What does this battery rule show?
    let battery = 59;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  17. 17.🔀 What does this PIN rule show?
    let pin = "17835";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  18. 18.🔀 What does this sign-up rule show?
    let age = 16;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  19. 19.🔀 Which badge does this quiz app show?
    let marks = 23;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Gold (c) Bronze
  20. 20.🔀 When does the else part run? (a) when the test is true (b) never (c) always (d) when the test is false
  21. 21.🔀 Which badge does this quiz app show?
    let marks = 89;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  22. 22.🔀 Which badge does this quiz app show?
    let marks = 45;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Gold (c) Silver
  23. 23.🔀 What does this PIN rule show?
    let pin = "77722";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  24. 24.🔀 In this course’s code, which sign tests “is equal to”? (a) = (b) !== (c) === (d) =>
  25. 25.🔀 What does this PIN rule show?
    let pin = "234";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  26. 26.🔀 What number does this shop app show?
    let total = 270;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  27. 27.🔀 What does this PIN rule show?
    let pin = "48922";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  28. 28.🔀 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
  29. 29.🔀 What does this PIN rule show?
    let pin = "65703";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  30. 30.🔀 What does this sign-up rule show?
    let age = 15;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  31. 31.🔀 Which badge does this quiz app show?
    let marks = 69;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Silver (c) Gold
  32. 32.🔀 Which badge does this quiz app show?
    let marks = 39;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  33. 33.🔀 What does this battery rule show?
    let battery = 22;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  34. 34.🔀 Which badge does this quiz app show?
    let marks = 70;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Gold (c) Bronze
  35. 35.🔀 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
  36. 36.🔀 What does this battery rule show?
    let battery = 30;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  37. 37.🔀 Which badge does this quiz app show?
    let marks = 24;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  38. 38.🔀 What does this battery rule show?
    let battery = 68;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  39. 39.🔀 What does this PIN rule show?
    let pin = "355";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  40. 40.🔀 What does this battery rule show?
    let battery = 69;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK

Answer key

  1. Use 4 digits
  2. Silver
  3. pick one of two actions
  4. Battery OK
  5. Battery OK
  6. Use 4 digits
  7. Gold
  8. Ask a parent
  9. 550
  10. Low battery
  11. Battery OK
  12. Battery OK
  13. Battery OK
  14. Battery OK
  15. Gold
  16. Battery OK
  17. Use 4 digits
  18. Welcome!
  19. Bronze
  20. when the test is false
  21. Gold
  22. Bronze
  23. Use 4 digits
  24. ===
  25. Use 4 digits
  26. 270
  27. Use 4 digits
  28. Welcome!
  29. Use 4 digits
  30. Welcome!
  31. Silver
  32. Bronze
  33. Battery OK
  34. Silver
  35. Ask a parent
  36. Battery OK
  37. Bronze
  38. Battery OK
  39. Use 4 digits
  40. Battery OK

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