App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 740 · 40 questions

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.

1. 1.🔁 What number does this code show?
   let marks = [11, 8, 14];
   let total = 0;
   for (let i = 0; i < marks.length; i++) {
     total = total + marks[i];
   }
   show(total);
2. 2.🔁 What number does this code show?
   let marks = [3, 17, 11];
   let total = 0;
   for (let i = 0; i < marks.length; i++) {
     total = total + marks[i];
   }
   show(total);
3. 3.🔁 What is the LAST line this code shows?
   let names = ["Riya", "Meera", "Zoya", "Aman"];
   for (let i = 0; i < names.length; i++) {
     show("Hi, " + names[i]);
   } (a) Hi, Meera (b) Hi, Zoya (c) Hi, Riya (d) Hi, Aman
4. 4.🔁 What is the LAST line this code shows?
   let names = ["Riya", "Aman", "Meera", "Zoya"];
   for (let i = 0; i < names.length; i++) {
     show("Hi, " + names[i]);
   } (a) Hi, Meera (b) Hi, Riya (c) Hi, Aman (d) Hi, Zoya
5. 5.🔁 What number does this code show?
   let runs = [15, 8, 18];
   let total = 0;
   for (let i = 0; i < runs.length; i++) {
     total = total + runs[i];
   }
   show(total);
6. 6.🔁 What number does this code show?
   let runs = [9, 14, 2, 7];
   let total = 0;
   for (let i = 0; i < runs.length; i++) {
     total = total + runs[i];
   }
   show(total);
7. 7.🔁 What number does this code show?
   let marks = [8, 5, 2, 1];
   let total = 0;
   for (let i = 0; i < marks.length; i++) {
     total = total + marks[i];
   }
   show(total);
8. 8.🔁 What number does this code show?
   let marks = [12, 3, 3];
   let total = 0;
   for (let i = 0; i < marks.length; i++) {
     total = total + marks[i];
   }
   show(total);
9. 9.🔁 A loop over a list of 5 items runs its body how many times? (a) 5 (b) 6 (c) 4 (d) 1
10. 10.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Riya", "Arjun", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Zoya (b) Hi, Riya (c) Hi, Meera (d) Hi, Arjun
11. 11.🔁 What number does this code show?
    let steps = [57, 90, 90, 83];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
12. 12.🔁 What is the LAST line this code shows?
    let names = ["Arjun", "Meera", "Zoya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Meera (b) Hi, Arjun (c) Hi, Zoya
13. 13.🔁 What number does this code show?
    let scores = [19, 15, 2];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
14. 14.🔁 What number does this code show?
    let scores = [13, 42, 92, 80];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
15. 15.🔁 What number does this code show?
    let runs = [2, 1, 3];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
16. 16.🔁 What number does this code show?
    let marks = [7, 13, 16];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
17. 17.🔁 list.length tells you ___. (a) how many items it has (b) the biggest item (c) the first item (d) the last item
18. 18.🔁 What number does this code show?
    let marks = [11, 57, 75, 46];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
19. 19.🔁 What number does this code show?
    let marks = [11, 7, 11];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
20. 20.🔁 What number does this code show?
    let runs = [15, 43, 80, 11, 11];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
21. 21.🔁 What number does this code show?
    let marks = [10, 12, 10];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
22. 22.🔁 What does a loop do? (a) deletes code (b) saves photos (c) draws icons (d) repeats code
23. 23.🔁 What number does this code show?
    let steps = [10, 23, 62, 29, 21];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
24. 24.🔁 What number does this code show?
    let runs = [4, 4, 11];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
25. 25.🔁 What number does this code show?
    let steps = [13, 10, 4];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
26. 26.🔁 What number does this code show?
    let runs = [16, 6, 1];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
27. 27.🔁 What number does this code show?
    let marks = [28, 63, 87, 61, 42];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
28. 28.🔁 What number does this code show?
    let runs = [38, 33, 67];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
29. 29.🔁 What number does this code show?
    let marks = [87, 36, 71, 95, 74];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
30. 30.🔁 What number does this code show?
    let marks = [35, 98, 59, 81];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
31. 31.🔁 What number does this code show?
    let steps = [12, 2, 11, 7];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
32. 32.🔁 What number does this code show?
    let runs = [8, 20, 20, 14, 14];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
33. 33.🔁 What number does this code show?
    let steps = [14, 7, 6, 13, 15];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
34. 34.🔁 What number does this code show?
    let marks = [14, 11, 89];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
35. 35.🔁 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
36. 36.🔁 What number does this code show?
    let marks = [49, 79, 22];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
37. 37.🔁 What number does this code show?
    let scores = [19, 38, 63, 15];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
38. 38.🔁 What number does this code show?
    let scores = [19, 61, 50, 42];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
39. 39.🔁 What number does this code show?
    let marks = [59, 91, 28];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);
40. 40.🔁 What number does this code show?
    let runs = [81, 25, 38];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);

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