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App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 805 · 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 number does this shop app show?
    let total = 240;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  2. 2.🔀 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!
  3. 3.🔀 What does this battery rule show?
    let battery = 38;
    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 = 17;
    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 = "302";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  6. 6.🔀 What does this battery rule show?
    let battery = 22;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  7. 7.🔀 What does if / else let an app do? (a) repeat forever (b) save a photo (c) pick one of two actions (d) draw a screen
  8. 8.🔀 Which badge does this quiz app show?
    let marks = 55;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  9. 9.🔀 Which badge does this quiz app show?
    let marks = 100;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  10. 10.🔀 What does this PIN rule show?
    let pin = "772";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  11. 11.🔀 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!
  12. 12.🔀 What does this PIN rule show?
    let pin = "452";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  13. 13.🔀 When does the else part run? (a) never (b) when the test is true (c) when the test is false (d) always
  14. 14.🔀 What does this battery rule show?
    let battery = 31;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  15. 15.🔀 With if / else if / else, how many parts run? (a) only one (b) none (c) two (d) all of them
  16. 16.🔀 What does this PIN rule show?
    let pin = "28581";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  17. 17.🔀 What number does this shop app show?
    let total = 790;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  18. 18.🔀 What does this sign-up rule show?
    let age = 11;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  19. 19.🔀 What does this battery rule show?
    let battery = 51;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  20. 20.🔀 What does this battery rule show?
    let battery = 45;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  21. 21.🔀 Which badge does this quiz app show?
    let marks = 25;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  22. 22.🔀 Which badge does this quiz app show?
    let marks = 22;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  23. 23.🔀 What does this battery rule show?
    let battery = 88;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  24. 24.🔀 What number does this shop app show?
    let total = 220;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  25. 25.🔀 What does this PIN rule show?
    let pin = "638";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  26. 26.🔀 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) Bronze (b) Gold (c) Silver
  27. 27.🔀 What does this PIN rule show?
    let pin = "248";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  28. 28.🔀 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
  29. 29.🔀 In this course’s code, which sign tests “is equal to”? (a) === (b) !== (c) => (d) =
  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.🔀 What does this battery rule show?
    let battery = 64;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  32. 32.🔀 What does this PIN rule show?
    let pin = "8357";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  33. 33.🔀 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) Silver (b) Gold (c) Bronze
  34. 34.🔀 What does this PIN rule show?
    let pin = "2912";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  35. 35.🔀 Which badge does this quiz app show?
    let marks = 56;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Bronze (c) Silver
  36. 36.🔀 Which badge does this quiz app show?
    let marks = 41;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Silver (c) Gold
  37. 37.🔀 What number does this shop app show?
    let total = 360;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  38. 38.🔀 What does this battery rule show?
    let battery = 60;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  39. 39.🔀 Which badge does this quiz app show?
    let marks = 72;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Gold (c) Silver
  40. 40.🔀 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

Answer key

  1. 240
  2. Ask a parent
  3. Battery OK
  4. Welcome!
  5. Use 4 digits
  6. Battery OK
  7. pick one of two actions
  8. Silver
  9. Gold
  10. Use 4 digits
  11. Welcome!
  12. Use 4 digits
  13. when the test is false
  14. Battery OK
  15. only one
  16. Use 4 digits
  17. 740
  18. Ask a parent
  19. Battery OK
  20. Battery OK
  21. Bronze
  22. Bronze
  23. Battery OK
  24. 220
  25. Use 4 digits
  26. Silver
  27. Use 4 digits
  28. Ask a parent
  29. ===
  30. Welcome!
  31. Battery OK
  32. PIN saved
  33. Gold
  34. PIN saved
  35. Silver
  36. Bronze
  37. 360
  38. Battery OK
  39. Silver
  40. Silver

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