← if / else: app rules lesson New set →

App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 408 · 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 sign-up rule show?
    let age = 14;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Welcome! (b) Ask a parent
  2. 2.🔀 When does the else part run? (a) when the test is false (b) always (c) when the test is true (d) never
  3. 3.🔀 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
  4. 4.🔀 What number does this shop app show?
    let total = 690;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  5. 5.🔀 What does this PIN rule show?
    let pin = "5766";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  6. 6.🔀 What does this PIN rule show?
    let pin = "5257";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  7. 7.🔀 What does this battery rule show?
    let battery = 4;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  8. 8.🔀 What does if / else let an app do? (a) draw a screen (b) repeat forever (c) pick one of two actions (d) save a photo
  9. 9.🔀 What does this battery rule show?
    let battery = 12;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  10. 10.🔀 What does this battery rule show?
    let battery = 56;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  11. 11.🔀 What number does this shop app show?
    let total = 650;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  12. 12.🔀 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
  13. 13.🔀 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!
  14. 14.🔀 What does this battery rule show?
    let battery = 46;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  15. 15.🔀 What does this PIN rule show?
    let pin = "5946";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  16. 16.🔀 What does this PIN rule show?
    let pin = "667";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  17. 17.🔀 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!
  18. 18.🔀 What number does this shop app show?
    let total = 550;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  19. 19.🔀 With if / else if / else, how many parts run? (a) none (b) all of them (c) two (d) only one
  20. 20.🔀 What does this battery rule show?
    let battery = 89;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery
  21. 21.🔀 What does >= mean? (a) not equal (b) less than (c) smaller or equal (d) greater than or equal
  22. 22.🔀 What does this PIN rule show?
    let pin = "677";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  23. 23.🔀 What does this battery rule show?
    let battery = 3;
    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 = 320;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
  25. 25.🔀 What does this PIN rule show?
    let pin = "45073";
    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 = 84;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Bronze (c) Gold
  27. 27.🔀 What does this PIN rule show?
    let pin = "803";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  28. 28.🔀 What does this PIN rule show?
    let pin = "75978";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  29. 29.🔀 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) Silver (b) Gold (c) Bronze
  30. 30.🔀 What does this sign-up rule show?
    let age = 8;
    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 = 70;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Low battery (b) Battery OK
  32. 32.🔀 In this course’s code, which sign tests “is equal to”? (a) !== (b) = (c) === (d) =>
  33. 33.🔀 What does this battery rule show?
    let battery = 20;
    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 = 62;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Bronze (c) Gold
  35. 35.🔀 What does this PIN rule show?
    let pin = "5887";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) Use 4 digits (b) PIN saved
  36. 36.🔀 Which badge does this quiz app show?
    let marks = 34;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    }
    (a) Silver (b) Bronze (c) Gold
  37. 37.🔀 What does this PIN rule show?
    let pin = "76392";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    }
    (a) PIN saved (b) Use 4 digits
  38. 38.🔀 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!
  39. 39.🔀 What does this sign-up rule show?
    let age = 13;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    }
    (a) Ask a parent (b) Welcome!
  40. 40.🔀 What does this battery rule show?
    let battery = 72;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    }
    (a) Battery OK (b) Low battery

Answer key

  1. Welcome!
  2. when the test is false
  3. Welcome!
  4. 640
  5. PIN saved
  6. PIN saved
  7. Low battery
  8. pick one of two actions
  9. Low battery
  10. Battery OK
  11. 600
  12. Ask a parent
  13. Ask a parent
  14. Battery OK
  15. PIN saved
  16. Use 4 digits
  17. Ask a parent
  18. 500
  19. only one
  20. Battery OK
  21. greater than or equal
  22. Use 4 digits
  23. Low battery
  24. 320
  25. Use 4 digits
  26. Gold
  27. Use 4 digits
  28. Use 4 digits
  29. Bronze
  30. Ask a parent
  31. Battery OK
  32. ===
  33. Battery OK
  34. Silver
  35. PIN saved
  36. Bronze
  37. Use 4 digits
  38. Ask a parent
  39. Welcome!
  40. Battery OK

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students