App Dev Worksheet: If Else Rules

App development lesson 18: if / else: app rules · Set 460 · 40 questions

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”.

1. 1.🔀 What number does this shop app show?
   let total = 360;
   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 number does this shop app show?
   let total = 510;
   if (total > 500) {
     total = total - 50;
   }
   show(total);
4. 4.🔀 What does if / else let an app do? (a) save a photo (b) pick one of two actions (c) repeat forever (d) draw a screen
5. 5.🔀 What does this PIN rule show?
   let pin = "7731";
   if (pin.length === 4) {
     show("PIN saved");
   } else {
     show("Use 4 digits");
   } (a) Use 4 digits (b) PIN saved
6. 6.🔀 What does >= mean? (a) not equal (b) smaller or equal (c) greater than or equal (d) less than
7. 7.🔀 What does this PIN rule show?
   let pin = "112";
   if (pin.length === 4) {
     show("PIN saved");
   } else {
     show("Use 4 digits");
   } (a) PIN saved (b) Use 4 digits
8. 8.🔀 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
9. 9.🔀 What number does this shop app show?
   let total = 740;
   if (total > 500) {
     total = total - 50;
   }
   show(total);
10. 10.🔀 What does this battery rule show?
    let battery = 90;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Battery OK (b) Low battery
11. 11.🔀 When does the else part run? (a) when the test is true (b) never (c) always (d) when the test is false
12. 12.🔀 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
13. 13.🔀 Which badge does this quiz app show?
    let marks = 59;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    } (a) Silver (b) Bronze (c) Gold
14. 14.🔀 What does this battery rule show?
    let battery = 79;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Battery OK (b) Low battery
15. 15.🔀 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
16. 16.🔀 What does this sign-up rule show?
    let age = 13;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    } (a) Welcome! (b) Ask a parent
17. 17.🔀 What does this battery rule show?
    let battery = 38;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Battery OK (b) Low battery
18. 18.🔀 What does this PIN rule show?
    let pin = "978";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    } (a) PIN saved (b) Use 4 digits
19. 19.🔀 What does this battery rule show?
    let battery = 93;
    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 = 88;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Battery OK (b) Low battery
21. 21.🔀 What does this PIN rule show?
    let pin = "1790";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    } (a) PIN saved (b) Use 4 digits
22. 22.🔀 What does this battery rule show?
    let battery = 91;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Low battery (b) Battery OK
23. 23.🔀 With if / else if / else, how many parts run? (a) two (b) only one (c) all of them (d) none
24. 24.🔀 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
25. 25.🔀 What number does this shop app show?
    let total = 630;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
26. 26.🔀 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
27. 27.🔀 Which badge does this quiz app show?
    let marks = 58;
    if (marks >= 80) {
      show("Gold");
    } else if (marks >= 50) {
      show("Silver");
    } else {
      show("Bronze");
    } (a) Bronze (b) Silver (c) Gold
28. 28.🔀 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) Bronze (b) Silver (c) Gold
29. 29.🔀 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!
30. 30.🔀 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
31. 31.🔀 Which badge does this quiz app show?
    let marks = 63;
    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 = "641";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    } (a) Use 4 digits (b) PIN saved
33. 33.🔀 What does this sign-up rule show?
    let age = 12;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    } (a) Ask a parent (b) Welcome!
34. 34.🔀 What does this battery rule show?
    let battery = 25;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Low battery (b) Battery OK
35. 35.🔀 What number does this shop app show?
    let total = 890;
    if (total > 500) {
      total = total - 50;
    }
    show(total);
36. 36.🔀 What does this battery rule show?
    let battery = 59;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Battery OK (b) Low battery
37. 37.🔀 What does this PIN rule show?
    let pin = "70755";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    } (a) Use 4 digits (b) PIN saved
38. 38.🔀 What does this sign-up rule show?
    let age = 17;
    if (age >= 13) {
      show("Welcome!");
    } else {
      show("Ask a parent");
    } (a) Ask a parent (b) Welcome!
39. 39.🔀 What does this battery rule show?
    let battery = 28;
    if (battery < 20) {
      show("Low battery");
    } else {
      show("Battery OK");
    } (a) Battery OK (b) Low battery
40. 40.🔀 What does this PIN rule show?
    let pin = "492";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    } (a) PIN saved (b) Use 4 digits

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