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App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 691 · 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.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 0, 1, 2, 3 (b) 0, 1, 2 (c) 3 (d) 1, 2, 3
  2. 2.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Arjun", "Riya", "Aman", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Riya (b) Hi, Zoya (c) Hi, Arjun (d) Hi, Kabir
  3. 3.🔁 What number does this code show?
    let runs = [18, 13, 1, 3];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  4. 4.🔁 A loop over a list of 5 items runs its body how many times? (a) 1 (b) 6 (c) 5 (d) 4
  5. 5.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Aman", "Kabir", "Arjun", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Riya (b) Hi, Aman (c) Hi, Kabir (d) Hi, Meera
  6. 6.🔁 What is the LAST line this code shows?
    let names = ["Zoya", "Kabir", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Zoya (b) Hi, Arjun (c) Hi, Kabir
  7. 7.🔁 What number does this code show?
    let runs = [13, 14, 12, 10];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
  8. 8.🔁 What number does this code show?
    let scores = [81, 76, 78];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
  9. 9.🔁 What number does this code show?
    let steps = [50, 22, 90, 35];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  10. 10.🔁 What number does this code show?
    let steps = [36, 74, 45];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  11. 11.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Arjun", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Meera (b) Hi, Arjun (c) Hi, Kabir (d) Hi, Riya
  12. 12.🔁 What number does this code show?
    let steps = [20, 4, 17, 12];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
  13. 13.🔁 list.length tells you ___. (a) the biggest item (b) the first item (c) how many items it has (d) the last item
  14. 14.🔁 What number does this code show?
    let marks = [6, 7, 12, 11, 13];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  15. 15.🔁 What number does this code show?
    let marks = [15, 10, 18, 14, 11];
    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 steps = [4, 15, 17];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
  17. 17.🔁 What number does this code show?
    let scores = [13, 15, 7, 19];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
  18. 18.🔁 What number does this code show?
    let marks = [4, 9, 1, 8];
    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 runs = [18, 11, 15, 12];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
  20. 20.🔁 What number does this code show?
    let runs = [13, 54, 68, 87];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  21. 21.🔁 What number does this code show?
    let runs = [5, 18, 6, 7, 1];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
  22. 22.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Riya", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Riya (b) Hi, Meera (c) Hi, Arjun
  23. 23.🔁 What does a loop do? (a) draws icons (b) deletes code (c) repeats code (d) saves photos
  24. 24.🔁 What number does this code show?
    let marks = [4, 13, 6, 17, 11];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  25. 25.🔁 What number does this code show?
    let scores = [9, 10, 12];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
  26. 26.🔁 What number does this code show?
    let scores = [16, 15, 10];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  27. 27.🔁 What number does this code show?
    let scores = [13, 20, 7, 15];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  28. 28.🔁 What number does this code show?
    let scores = [6, 8, 9, 9];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  29. 29.🔁 What is the LAST line this code shows?
    let names = ["Aman", "Zoya", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Aman (b) Hi, Zoya (c) Hi, Meera
  30. 30.🔁 What number does this code show?
    let runs = [16, 6, 14, 6];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  31. 31.🔁 What number does this code show?
    let marks = [7, 2, 1, 3];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  32. 32.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Aman", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Zoya (b) Hi, Kabir (c) Hi, Aman
  33. 33.🔁 What number does this code show?
    let scores = [1, 6, 3, 14];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
  34. 34.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Arjun", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Arjun (b) Hi, Kabir (c) Hi, Zoya
  35. 35.🔁 What number does this code show?
    let steps = [91, 44, 61];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
  36. 36.🔁 What is the LAST line this code shows?
    let names = ["Aman", "Zoya", "Riya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }
    (a) Hi, Zoya (b) Hi, Riya (c) Hi, Aman
  37. 37.🔁 What number does this code show?
    let marks = [11, 1, 8];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
  38. 38.🔁 What number does this code show?
    let steps = [6, 6, 1, 16, 13];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
  39. 39.🔁 What number does this code show?
    let scores = [5, 12, 17, 12, 15];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  40. 40.🔁 What number does this code show?
    let runs = [10, 20, 11, 20];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);

Answer key

  1. 0, 1, 2
  2. Hi, Zoya
  3. 35
  4. 5
  5. Hi, Meera
  6. Hi, Arjun
  7. 14
  8. 3
  9. 2
  10. 2
  11. Hi, Meera
  12. 53
  13. how many items it has
  14. 49
  15. 68
  16. 17
  17. 54
  18. 22
  19. 18
  20. 3
  21. 18
  22. Hi, Arjun
  23. repeats code
  24. 51
  25. 31
  26. 16
  27. 20
  28. 9
  29. Hi, Meera
  30. 42
  31. 13
  32. Hi, Zoya
  33. 24
  34. Hi, Zoya
  35. 2
  36. Hi, Riya
  37. 11
  38. 16
  39. 17
  40. 61

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