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App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 649 · 40 questions
TalentJR

Developer's tip (One by one): for (let i = 0; i < list.length; i++) visits every item, from position 0. Total: add each item. Count: add 1 when the test is true. Best: keep the biggest so far. The body runs once per item: a list of 5 runs it 5 times.

NameDateTime takenScore ___ / 40
  1. 1.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Riya", "Zoya", "Meera", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Zoya (b) Hi, Aman (c) Hi, Kabir (d) Hi, Riya
  2. 2.🔁 A loop over a list of 5 items runs its body how many times? (a) 1 (b) 4 (c) 6 (d) 5
  3. 3.🔁 What number does this code show?
    let marks = [11, 18, 7];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
  4. 4.🔁 What number does this code show?
    let steps = [40, 48, 31];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
  5. 5.🔁 What does a loop do? (a) draws icons (b) deletes code (c) repeats code (d) saves photos
  6. 6.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Kabir (b) Hi, Zoya (c) Hi, Riya
  7. 7.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Zoya", "Aman", "Kabir"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Riya (b) Hi, Zoya (c) Hi, Aman (d) Hi, Kabir
  8. 8.🔁 What number does this code show?
    let steps = [53, 88, 91, 43];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
  9. 9.🔁 What number does this code show?
    let scores = [93, 98, 17];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  10. 10.🔁 What number does this code show?
    let steps = [90, 47, 14];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  11. 11.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 1, 2, 3 (b) 3 (c) 0, 1, 2 (d) 0, 1, 2, 3
  12. 12.🔁 What number does this code show?
    let steps = [27, 89, 23];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  13. 13.🔁 What number does this code show?
    let scores = [4, 20, 9, 1];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
  14. 14.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Aman", "Meera", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Zoya (b) Hi, Aman (c) Hi, Kabir (d) Hi, Riya
  15. 15.🔁 What number does this code show?
    let marks = [11, 20, 2, 19, 17];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  16. 16.🔁 What number does this code show?
    let runs = [82, 11, 71, 96];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
  17. 17.🔁 What is the LAST line this code shows?
    let names = ["Aman", "Kabir", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Aman (b) Hi, Meera (c) Hi, Kabir
  18. 18.🔁 What number does this code show?
    let marks = [19, 3, 9, 7, 18];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  19. 19.🔁 What number does this code show?
    let scores = [4, 5, 20];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  20. 20.🔁 What number does this code show?
    let scores = [19, 11, 14, 18, 10];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  21. 21.🔁 What number does this code show?
    let steps = [13, 18, 11];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
  22. 22.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Aman", "Riya", "Arjun", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Aman (b) Hi, Meera (c) Hi, Zoya (d) Hi, Riya
  23. 23.🔁 What number does this code show?
    let runs = [3, 18, 11, 8, 20];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  24. 24.🔁 What number does this code show?
    let runs = [13, 12, 6];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  25. 25.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Arjun", "Meera", "Riya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Arjun (b) Hi, Riya (c) Hi, Kabir (d) Hi, Meera
  26. 26.🔁 What number does this code show?
    let scores = [28, 92, 15];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  27. 27.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Meera (b) Hi, Kabir (c) Hi, Riya
  28. 28.🔁 What number does this code show?
    let steps = [5, 1, 16];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
  29. 29.🔁 What number does this code show?
    let steps = [99, 93, 85];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  30. 30.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Aman", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Aman (b) Hi, Riya (c) Hi, Zoya
  31. 31.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Meera", "Zoya", "Riya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Riya (b) Hi, Meera (c) Hi, Kabir (d) Hi, Zoya
  32. 32.🔁 What number does this code show?
    let steps = [13, 12, 20, 10, 9];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
  33. 33.🔁 What is the LAST line this code shows?
    let names = ["Zoya", "Meera", "Aman", "Kabir"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Zoya (b) Hi, Kabir (c) Hi, Aman (d) Hi, Meera
  34. 34.🔁 What number does this code show?
    let runs = [10, 5, 1];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  35. 35.🔁 What number does this code show?
    let steps = [5, 6, 18, 6];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
  36. 36.🔁 What number does this code show?
    let marks = [2, 1, 20];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  37. 37.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Riya", "Zoya", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Riya (b) Hi, Zoya (c) Hi, Meera (d) Hi, Aman
  38. 38.🔁 What number does this code show?
    let steps = [18, 7, 6, 13];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
  39. 39.🔁 list.length tells you ___. (a) the last item (b) the first item (c) the biggest item (d) how many items it has
  40. 40.🔁 What number does this code show?
    let steps = [87, 10, 66, 17, 35];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);

Answer key

  1. Hi, Aman
  2. 5
  3. 18
  4. 0
  5. repeats code
  6. Hi, Zoya
  7. Hi, Kabir
  8. 2
  9. 2
  10. 2
  11. 0, 1, 2
  12. 1
  13. 34
  14. Hi, Zoya
  15. 69
  16. 3
  17. Hi, Meera
  18. 56
  19. 20
  20. 19
  21. 42
  22. Hi, Zoya
  23. 60
  24. 31
  25. Hi, Riya
  26. 1
  27. Hi, Meera
  28. 22
  29. 3
  30. Hi, Zoya
  31. Hi, Riya
  32. 20
  33. Hi, Kabir
  34. 16
  35. 18
  36. 23
  37. Hi, Aman
  38. 44
  39. how many items it has
  40. 2

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