App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 603 · 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 is the LAST line this code shows?
   let names = ["Meera", "Aman", "Zoya", "Kabir"];
   for (let i = 0; i < names.length; i++) {
     show("Hi, " + names[i]);
   } (a) Hi, Aman (b) Hi, Kabir (c) Hi, Meera (d) Hi, Zoya
2. 2.🔁 What number does this code show?
   let scores = [47, 26, 73, 40];
   let count = 0;
   for (let i = 0; i < scores.length; i++) {
     if (scores[i] >= 60) {
       count = count + 1;
     }
   }
   show(count);
3. 3.🔁 What number does this code show?
   let runs = [86, 68, 13];
   let count = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] >= 60) {
       count = count + 1;
     }
   }
   show(count);
4. 4.🔁 What number does this code show?
   let scores = [16, 9, 8];
   let total = 0;
   for (let i = 0; i < scores.length; i++) {
     total = total + scores[i];
   }
   show(total);
5. 5.🔁 What number does this code show?
   let scores = [12, 3, 3];
   let best = 0;
   for (let i = 0; i < scores.length; i++) {
     if (scores[i] > best) {
       best = scores[i];
     }
   }
   show(best);
6. 6.🔁 What does a loop do? (a) deletes code (b) draws icons (c) repeats code (d) saves photos
7. 7.🔁 What number does this code show?
   let runs = [17, 88, 87];
   let count = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] >= 50) {
       count = count + 1;
     }
   }
   show(count);
8. 8.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 0, 1, 2 (b) 1, 2, 3 (c) 0, 1, 2, 3 (d) 3
9. 9.🔁 What number does this code show?
   let marks = [19, 4, 20, 10, 12];
   let total = 0;
   for (let i = 0; i < marks.length; i++) {
     total = total + marks[i];
   }
   show(total);
10. 10.🔁 What number does this code show?
    let scores = [3, 6, 14];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
11. 11.🔁 Why use a loop to show 100 messages? (a) it uses more lines (b) it is slower (c) it hides them (d) less code to write
12. 12.🔁 What number does this code show?
    let scores = [16, 4, 19, 15, 13];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
13. 13.🔁 What number does this code show?
    let marks = [17, 16, 5];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
14. 14.🔁 What is the LAST line this code shows?
    let names = ["Arjun", "Meera", "Aman", "Riya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Riya (b) Hi, Meera (c) Hi, Aman (d) Hi, Arjun
15. 15.🔁 What number does this code show?
    let steps = [15, 17, 15, 5];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
16. 16.🔁 What number does this code show?
    let steps = [16, 8, 9, 17, 20];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
17. 17.🔁 What number does this code show?
    let scores = [1, 19, 1];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
18. 18.🔁 A loop over a list of 5 items runs its body how many times? (a) 1 (b) 4 (c) 5 (d) 6
19. 19.🔁 What number does this code show?
    let runs = [4, 5, 20];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
20. 20.🔁 What number does this code show?
    let steps = [24, 41, 50, 59, 33];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
21. 21.🔁 What number does this code show?
    let runs = [5, 2, 4];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
22. 22.🔁 What number does this code show?
    let runs = [9, 19, 12];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
23. 23.🔁 What number does this code show?
    let marks = [4, 15, 20, 4, 2];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
24. 24.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Arjun", "Kabir"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Riya (b) Hi, Kabir (c) Hi, Arjun
25. 25.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Meera", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Meera (b) Hi, Riya (c) Hi, Arjun
26. 26.🔁 What number does this code show?
    let marks = [19, 18, 5];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
27. 27.🔁 What number does this code show?
    let scores = [97, 91, 97];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
28. 28.🔁 What number does this code show?
    let runs = [2, 18, 2];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
29. 29.🔁 list.length tells you ___. (a) the last item (b) the biggest item (c) the first item (d) how many items it has
30. 30.🔁 What number does this code show?
    let scores = [11, 10, 15];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
31. 31.🔁 What number does this code show?
    let scores = [2, 2, 16, 9];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
32. 32.🔁 What number does this code show?
    let runs = [9, 5, 7];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
33. 33.🔁 What number does this code show?
    let scores = [8, 1, 8];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
34. 34.🔁 What number does this code show?
    let runs = [17, 14, 16];
    let best = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] > best) {
        best = runs[i];
      }
    }
    show(best);
35. 35.🔁 What number does this code show?
    let marks = [7, 18, 5];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
36. 36.🔁 What number does this code show?
    let marks = [7, 9, 2];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
37. 37.🔁 What number does this code show?
    let marks = [16, 2, 14, 16];
    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 runs = [20, 16, 59];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
39. 39.🔁 What number does this code show?
    let marks = [7, 16, 3, 19, 9];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
40. 40.🔁 What number does this code show?
    let scores = [5, 5, 20];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);

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