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App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 508 · 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 = "5635";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  2. 2.🔀 What number does this shop app show?
    let total = 830;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  3. 3.🔀 What does if / else let an app do? (a) repeat forever (b) draw a screen (c) pick one of two actions (d) save a photo
  4. 4.🔀 What number does this shop app show?
    let total = 740;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  5. 5.🔀 What does >= mean? (a) not equal (b) greater than or equal (c) less than (d) smaller or equal
  6. 6.🔀 What does this sign-up rule show?
    let age = 10;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  7. 7.🔀 What does this sign-up rule show?
    let age = 17;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  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 does this PIN rule show?
    let pin = "529";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  10. 10.🔀 What does this battery rule show?
    let battery = 32;
    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 = 2;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  12. 12.🔀 What number does this shop app show?
    let total = 270;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  13. 13.🔀 In this course’s code, which sign tests “is equal to”? (a) => (b) !== (c) === (d) =
  14. 14.🔀 What does this PIN rule show?
    let pin = "89301";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  15. 15.🔀 What does this PIN rule show?
    let pin = "142";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  16. 16.🔀 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!
  17. 17.🔀 With if / else if / else, how many parts run? (a) two (b) only one (c) all of them (d) none
  18. 18.🔀 What does this battery rule show?
    let battery = 77;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  19. 19.🔀 What does this battery rule show?
    let battery = 15;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  20. 20.🔀 What does this sign-up rule show?
    let age = 14;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  21. 21.🔀 When does the else part run? (a) when the test is false (b) never (c) always (d) when the test is true
  22. 22.🔀 What number does this shop app show?
    let total = 200;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  23. 23.🔀 What number does this shop app show?
    let total = 780;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  24. 24.🔀 What does this battery rule show?
    let battery = 62;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  25. 25.🔀 Which badge does this quiz app show?
    let marks = 74;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  26. 26.🔀 What does this battery rule show?
    let battery = 24;
    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 = "5671";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  28. 28.🔀 Which badge does this quiz app show?
    let marks = 62;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  29. 29.🔀 What does this sign-up rule show?
    let age = 16;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  30. 30.🔀 What number does this shop app show?
    let total = 580;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  31. 31.🔀 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
  32. 32.🔀 What does this PIN rule show?
    let pin = "9834";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  33. 33.🔀 What does this battery rule show?
    let battery = 41;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  34. 34.🔀 What does this PIN rule show?
    let pin = "573";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  35. 35.🔀 What number does this shop app show?
    let total = 730;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  36. 36.🔀 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
  37. 37.🔀 What does this sign-up rule show?
    let age = 9;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  38. 38.🔀 What does this PIN rule show?
    let pin = "90130";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  39. 39.🔀 What does this PIN rule show?
    let pin = "30051";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  40. 40.🔀 What does this PIN rule show?
    let pin = "67266";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits

Answer key

  1. PIN saved
  2. 780
  3. pick one of two actions
  4. 690
  5. greater than or equal
  6. Ask a parent
  7. Welcome!
  8. Ask a parent
  9. Use 4 digits
  10. Battery OK
  11. Low battery
  12. 270
  13. ===
  14. Use 4 digits
  15. Use 4 digits
  16. Welcome!
  17. only one
  18. Battery OK
  19. Low battery
  20. Welcome!
  21. when the test is false
  22. 200
  23. 730
  24. Battery OK
  25. Silver
  26. Battery OK
  27. PIN saved
  28. Silver
  29. Welcome!
  30. 530
  31. Ask a parent
  32. PIN saved
  33. Battery OK
  34. Use 4 digits
  35. 680
  36. Battery OK
  37. Ask a parent
  38. Use 4 digits
  39. Use 4 digits
  40. Use 4 digits

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