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App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 603 · 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 if / else let an app do? (a) draw a screen (b) repeat forever (c) save a photo (d) pick one of two actions
  2. 2.🔀 What does this PIN rule show?
    let pin = "273";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  3. 3.🔀 What number does this shop app show?
    let total = 340;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  4. 4.🔀 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!
  5. 5.🔀 What does this battery rule show?
    let battery = 29;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  6. 6.🔀 What does this battery rule show?
    let battery = 11;
    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 = 25;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Gold (c) Bronze
  8. 8.🔀 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
  9. 9.🔀 What does this battery rule show?
    let battery = 50;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  10. 10.🔀 Which badge does this quiz app show?
    let marks = 49;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Gold (c) Bronze
  11. 11.🔀 What number does this shop app show?
    let total = 620;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  12. 12.🔀 What does this PIN rule show?
    let pin = "9400";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  13. 13.🔀 What does this battery rule show?
    let battery = 61;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  14. 14.🔀 Which badge does this quiz app show?
    let marks = 44;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Bronze (b) Gold (c) Silver
  15. 15.🔀 Which badge does this quiz app show?
    let marks = 60;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  16. 16.🔀 What does this battery rule show?
    let battery = 10;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  17. 17.🔀 What number does this shop app show?
    let total = 510;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  18. 18.🔀 What does this battery rule show?
    let battery = 68;
    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 = 98;
    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 = 11;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  21. 21.🔀 What number does this shop app show?
    let total = 610;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  22. 22.🔀 What does this battery rule show?
    let battery = 74;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  23. 23.🔀 What number does this shop app show?
    let total = 790;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  24. 24.🔀 What does this battery rule show?
    let battery = 14;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  25. 25.🔀 When does the else part run? (a) never (b) always (c) when the test is true (d) when the test is false
  26. 26.🔀 What number does this shop app show?
    let total = 330;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  27. 27.🔀 What does this sign-up rule show?
    let age = 12;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  28. 28.🔀 Which badge does this quiz app show?
    let marks = 26;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Gold (b) Silver (c) Bronze
  29. 29.🔀 What does this PIN rule show?
    let pin = "95256";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  30. 30.🔀 What does >= mean? (a) less than (b) not equal (c) greater than or equal (d) smaller or equal
  31. 31.🔀 With if / else if / else, how many parts run? (a) none (b) two (c) all of them (d) only one
  32. 32.🔀 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) Silver (b) Gold (c) Bronze
  33. 33.🔀 What does this battery rule show?
    let battery = 33;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  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) Gold (b) Bronze (c) Silver
  35. 35.🔀 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) Bronze (b) Gold (c) Silver
  36. 36.🔀 What does this battery rule show?
    let battery = 26;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  37. 37.🔀 What does this battery rule show?
    let battery = 1;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  38. 38.🔀 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
  39. 39.🔀 What does this PIN rule show?
    let pin = "10337";
    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 = "146";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved

Answer key

  1. pick one of two actions
  2. Use 4 digits
  3. 340
  4. Ask a parent
  5. Battery OK
  6. Low battery
  7. Bronze
  8. Battery OK
  9. Battery OK
  10. Bronze
  11. 570
  12. PIN saved
  13. Battery OK
  14. Bronze
  15. Silver
  16. Low battery
  17. 460
  18. Battery OK
  19. Battery OK
  20. Ask a parent
  21. 560
  22. Battery OK
  23. 740
  24. Low battery
  25. when the test is false
  26. 330
  27. Ask a parent
  28. Bronze
  29. Use 4 digits
  30. greater than or equal
  31. only one
  32. Silver
  33. Battery OK
  34. Silver
  35. Silver
  36. Battery OK
  37. Low battery
  38. Ask a parent
  39. Use 4 digits
  40. Use 4 digits

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