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App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 144 · 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 = ["Riya", "Zoya", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Aman (b) Hi, Riya (c) Hi, Zoya
  2. 2.🔁 What number does this code show?
    let marks = [94, 54, 70, 44, 86];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  3. 3.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Zoya", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Kabir (b) Hi, Meera (c) Hi, Zoya
  4. 4.🔁 What number does this code show?
    let scores = [6, 8, 3, 15];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
  5. 5.🔁 What number does this code show?
    let runs = [91, 57, 32];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  6. 6.🔁 What number does this code show?
    let marks = [73, 15, 38];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  7. 7.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Kabir", "Riya", "Aman", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Meera (b) Hi, Kabir (c) Hi, Arjun (d) Hi, Riya
  8. 8.🔁 What number does this code show?
    let runs = [81, 71, 16, 61, 27];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
  9. 9.🔁 What number does this code show?
    let steps = [3, 13, 7, 6];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
  10. 10.🔁 What is the LAST line this code shows?
    let names = ["Arjun", "Zoya", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Aman (b) Hi, Zoya (c) Hi, Arjun
  11. 11.🔁 What number does this code show?
    let runs = [64, 67, 34, 90, 11];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
  12. 12.🔁 What number does this code show?
    let marks = [3, 18, 18, 4];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  13. 13.🔁 What number does this code show?
    let runs = [2, 5, 8, 3, 16];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  14. 14.🔁 What number does this code show?
    let scores = [51, 18, 86, 44, 48];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  15. 15.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Arjun", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Zoya (b) Hi, Riya (c) Hi, Kabir (d) Hi, Arjun
  16. 16.🔁 Why use a loop to show 100 messages? (a) it hides them (b) it is slower (c) it uses more lines (d) less code to write
  17. 17.🔁 What number does this code show?
    let marks = [3, 1, 14, 10];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
  18. 18.🔁 What number does this code show?
    let marks = [46, 35, 24];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
  19. 19.🔁 What is the LAST line this code shows?
    let names = ["Aman", "Riya", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Zoya (b) Hi, Aman (c) Hi, Riya
  20. 20.🔁 What number does this code show?
    let marks = [57, 46, 14, 85];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  21. 21.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Zoya", "Kabir", "Riya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Meera (b) Hi, Kabir (c) Hi, Zoya (d) Hi, Riya
  22. 22.🔁 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, Zoya (b) Hi, Kabir (c) Hi, Aman (d) Hi, Riya
  23. 23.🔁 What number does this code show?
    let marks = [20, 94, 25];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  24. 24.🔁 What number does this code show?
    let runs = [14, 34, 85, 69];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
  25. 25.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 3 (b) 0, 1, 2 (c) 0, 1, 2, 3 (d) 1, 2, 3
  26. 26.🔁 What number does this code show?
    let steps = [4, 7, 13];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
  27. 27.🔁 What number does this code show?
    let scores = [4, 4, 9, 2, 4];
    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 runs = [17, 15, 7, 11, 2];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  29. 29.🔁 What number does this code show?
    let marks = [50, 52, 86, 73, 56];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  30. 30.🔁 What is the LAST line this code shows?
    let names = ["Arjun", "Meera", "Kabir"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Arjun (b) Hi, Kabir (c) Hi, Meera
  31. 31.🔁 What number does this code show?
    let steps = [37, 68, 80];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  32. 32.🔁 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, Aman (c) Hi, Riya
  33. 33.🔁 What is the LAST line this code shows?
    let names = ["Arjun", "Zoya", "Aman", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Arjun (b) Hi, Aman (c) Hi, Meera (d) Hi, Zoya
  34. 34.🔁 What number does this code show?
    let scores = [13, 19, 6];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
  35. 35.🔁 What number does this code show?
    let runs = [99, 95, 27, 62, 51];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
  36. 36.🔁 What number does this code show?
    let steps = [14, 19, 14, 9];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
  37. 37.🔁 What number does this code show?
    let runs = [19, 8, 6];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
  38. 38.🔁 What number does this code show?
    let scores = [76, 93, 68];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
  39. 39.🔁 What does a loop do? (a) draws icons (b) repeats code (c) saves photos (d) deletes code
  40. 40.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Meera", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    }     (a) Hi, Riya (b) Hi, Arjun (c) Hi, Meera (d) Hi, Kabir

Answer key

  1. Hi, Aman
  2. 4
  3. Hi, Meera
  4. 15
  5. 2
  6. 1
  7. Hi, Arjun
  8. 2
  9. 13
  10. Hi, Aman
  11. 3
  12. 43
  13. 34
  14. 4
  15. Hi, Zoya
  16. less code to write
  17. 28
  18. 0
  19. Hi, Zoya
  20. 2
  21. Hi, Riya
  22. Hi, Kabir
  23. 1
  24. 1
  25. 0, 1, 2
  26. 24
  27. 9
  28. 52
  29. 5
  30. Hi, Kabir
  31. 2
  32. Hi, Riya
  33. Hi, Meera
  34. 38
  35. 4
  36. 19
  37. 33
  38. 3
  39. repeats code
  40. Hi, Arjun

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