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App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 291 · 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.🔀 Which badge does this quiz app show?
    let marks = 78;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  2. 2.🔀 When does the else part run? (a) always (b) when the test is true (c) never (d) when the test is false
  3. 3.🔀 What does this PIN rule show?
    let pin = "19333";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  4. 4.🔀 What does this PIN rule show?
    let pin = "45440";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  5. 5.🔀 What does this battery rule show?
    let battery = 99;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  6. 6.🔀 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
  7. 7.🔀 What does this PIN rule show?
    let pin = "747";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  8. 8.🔀 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
  9. 9.🔀 What number does this shop app show?
    let total = 380;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  10. 10.🔀 What does this battery rule show?
    let battery = 53;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  11. 11.🔀 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!
  12. 12.🔀 What does this sign-up rule show?
    let age = 13;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  13. 13.🔀 Which badge does this quiz app show?
    let marks = 94;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  14. 14.🔀 What does this battery rule show?
    let battery = 10;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  15. 15.🔀 In this course’s code, which sign tests “is equal to”? (a) = (b) !== (c) === (d) =>
  16. 16.🔀 What does this PIN rule show?
    let pin = "21218";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  17. 17.🔀 What does if / else let an app do? (a) draw a screen (b) repeat forever (c) save a photo (d) pick one of two actions
  18. 18.🔀 What does this battery rule show?
    let battery = 82;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  19. 19.🔀 What does this PIN rule show?
    let pin = "491";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  20. 20.🔀 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!
  21. 21.🔀 What does this PIN rule show?
    let pin = "43013";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  22. 22.🔀 What does this battery rule show?
    let battery = 30;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  23. 23.🔀 What does this PIN rule show?
    let pin = "20361";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  24. 24.🔀 What does this PIN rule show?
    let pin = "47589";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  25. 25.🔀 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!
  26. 26.🔀 What does this PIN rule show?
    let pin = "41268";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  27. 27.🔀 What does this battery rule show?
    let battery = 92;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  28. 28.🔀 What does this battery rule show?
    let battery = 29;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  29. 29.🔀 What does this sign-up rule show?
    let age = 12;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  30. 30.🔀 What does this battery rule show?
    let battery = 69;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  31. 31.🔀 Which badge does this quiz app show?
    let marks = 61;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Gold (c) Silver
  32. 32.🔀 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!
  33. 33.🔀 With if / else if / else, how many parts run? (a) two (b) only one (c) none (d) all of them
  34. 34.🔀 What does >= mean? (a) less than (b) not equal (c) greater than or equal (d) smaller or equal
  35. 35.🔀 Which badge does this quiz app show?
    let marks = 97;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Silver (c) Gold
  36. 36.🔀 What does this PIN rule show?
    let pin = "49065";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  37. 37.🔀 What number does this shop app show?
    let total = 750;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  38. 38.🔀 What does this PIN rule show?
    let pin = "58264";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  39. 39.🔀 What number does this shop app show?
    let total = 590;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  40. 40.🔀 What number does this shop app show?
    let total = 530;
    if (total > 500) {
      total = total - 50;
    }
    show(total);

Answer key

  1. Silver
  2. when the test is false
  3. Use 4 digits
  4. Use 4 digits
  5. Battery OK
  6. Ask a parent
  7. Use 4 digits
  8. Battery OK
  9. 380
  10. Battery OK
  11. Welcome!
  12. Welcome!
  13. Gold
  14. Low battery
  15. ===
  16. Use 4 digits
  17. pick one of two actions
  18. Battery OK
  19. Use 4 digits
  20. Welcome!
  21. Use 4 digits
  22. Battery OK
  23. Use 4 digits
  24. Use 4 digits
  25. Welcome!
  26. Use 4 digits
  27. Battery OK
  28. Battery OK
  29. Ask a parent
  30. Battery OK
  31. Silver
  32. Ask a parent
  33. only one
  34. greater than or equal
  35. Gold
  36. Use 4 digits
  37. 700
  38. Use 4 digits
  39. 540
  40. 480

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