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App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 400 · 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.🔀 With if / else if / else, how many parts run? (a) two (b) all of them (c) only one (d) none
  2. 2.🔀 What does if / else let an app do? (a) save a photo (b) repeat forever (c) pick one of two actions (d) draw a screen
  3. 3.🔀 In this course’s code, which sign tests “is equal to”? (a) === (b) = (c) !== (d) =>
  4. 4.🔀 What does this battery rule show?
    let battery = 35;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }     (a) Battery OK (b) Low battery
  5. 5.🔀 Which badge does this quiz app show?
    let marks = 87;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }     (a) Gold (b) Silver (c) Bronze
  6. 6.🔀 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
  7. 7.🔀 Which badge does this quiz app show?
    let marks = 57;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }     (a) Gold (b) Silver (c) Bronze
  8. 8.🔀 Which badge does this quiz app show?
    let marks = 43;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }     (a) Bronze (b) Gold (c) Silver
  9. 9.🔀 What does this PIN rule show?
    let pin = "70321";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) Use 4 digits (b) PIN saved
  10. 10.🔀 What number does this shop app show?
    let total = 300;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  11. 11.🔀 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
  12. 12.🔀 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!
  13. 13.🔀 What does this PIN rule show?
    let pin = "2879";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) Use 4 digits (b) PIN saved
  14. 14.🔀 What number does this shop app show?
    let total = 250;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  15. 15.🔀 When does the else part run? (a) when the test is true (b) when the test is false (c) always (d) never
  16. 16.🔀 What number does this shop app show?
    let total = 410;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  17. 17.🔀 What does this PIN rule show?
    let pin = "57384";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) PIN saved (b) Use 4 digits
  18. 18.🔀 What number does this shop app show?
    let total = 440;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  19. 19.🔀 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
  20. 20.🔀 What does this PIN rule show?
    let pin = "25056";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) PIN saved (b) Use 4 digits
  21. 21.🔀 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
  22. 22.🔀 What does this battery rule show?
    let battery = 66;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }     (a) Low battery (b) Battery OK
  23. 23.🔀 What number does this shop app show?
    let total = 840;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  24. 24.🔀 What does this battery rule show?
    let battery = 45;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }     (a) Battery OK (b) Low battery
  25. 25.🔀 What does this battery rule show?
    let battery = 8;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }     (a) Low battery (b) Battery OK
  26. 26.🔀 What does this PIN rule show?
    let pin = "73521";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) PIN saved (b) Use 4 digits
  27. 27.🔀 What does this battery rule show?
    let battery = 21;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }     (a) Battery OK (b) Low battery
  28. 28.🔀 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
  29. 29.🔀 What number does this shop app show?
    let total = 310;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  30. 30.🔀 What does this sign-up rule show?
    let age = 9;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }     (a) Welcome! (b) Ask a parent
  31. 31.🔀 Which badge does this quiz app show?
    let marks = 40;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }     (a) Silver (b) Bronze (c) Gold
  32. 32.🔀 What does this PIN rule show?
    let pin = "874";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) PIN saved (b) Use 4 digits
  33. 33.🔀 What does this PIN rule show?
    let pin = "5915";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }     (a) PIN saved (b) Use 4 digits
  34. 34.🔀 What does >= mean? (a) not equal (b) smaller or equal (c) greater than or equal (d) less than
  35. 35.🔀 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
  36. 36.🔀 What number does this shop app show?
    let total = 640;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  37. 37.🔀 What number does this shop app show?
    let total = 850;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  38. 38.🔀 What number does this shop app show?
    let total = 510;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  39. 39.🔀 What does this battery rule show?
    let battery = 49;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }     (a) Battery OK (b) Low battery
  40. 40.🔀 What number does this shop app show?
    let total = 280;
    if (total > 500) {
      total = total - 50;
    }
    show(total);

Answer key

  1. only one
  2. pick one of two actions
  3. ===
  4. Battery OK
  5. Gold
  6. Battery OK
  7. Silver
  8. Bronze
  9. Use 4 digits
  10. 300
  11. Ask a parent
  12. Welcome!
  13. PIN saved
  14. 250
  15. when the test is false
  16. 410
  17. Use 4 digits
  18. 440
  19. Welcome!
  20. Use 4 digits
  21. Ask a parent
  22. Battery OK
  23. 790
  24. Battery OK
  25. Low battery
  26. Use 4 digits
  27. Battery OK
  28. Battery OK
  29. 310
  30. Ask a parent
  31. Bronze
  32. Use 4 digits
  33. PIN saved
  34. greater than or equal
  35. Low battery
  36. 590
  37. 800
  38. 460
  39. Battery OK
  40. 280

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