App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 8 · 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 runs = [11, 4, 8, 16];
   let best = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] > best) {
       best = runs[i];
     }
   }
   show(best);
2. 2.🔁 What number does this code show?
   let marks = [34, 36, 35, 86, 64];
   let count = 0;
   for (let i = 0; i < marks.length; i++) {
     if (marks[i] >= 40) {
       count = count + 1;
     }
   }
   show(count);
3. 3.🔁 What number does this code show?
   let marks = [71, 74, 42, 60];
   let count = 0;
   for (let i = 0; i < marks.length; i++) {
     if (marks[i] >= 50) {
       count = count + 1;
     }
   }
   show(count);
4. 4.🔁 What number does this code show?
   let scores = [10, 7, 7];
   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 scores = [16, 8, 17];
   let total = 0;
   for (let i = 0; i < scores.length; i++) {
     total = total + scores[i];
   }
   show(total);
6. 6.🔁 What number does this code show?
   let steps = [17, 11, 12];
   let total = 0;
   for (let i = 0; i < steps.length; i++) {
     total = total + steps[i];
   }
   show(total);
7. 7.🔁 What number does this code show?
   let runs = [13, 5, 2, 10, 12];
   let best = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] > best) {
       best = runs[i];
     }
   }
   show(best);
8. 8.🔁 What is the LAST line this code shows?
   let names = ["Zoya", "Aman", "Arjun"];
   for (let i = 0; i < names.length; i++) {
     show("Hi, " + names[i]);
   } (a) Hi, Aman (b) Hi, Arjun (c) Hi, Zoya
9. 9.🔁 What number does this code show?
   let steps = [72, 64, 43, 79, 82];
   let count = 0;
   for (let i = 0; i < steps.length; i++) {
     if (steps[i] >= 50) {
       count = count + 1;
     }
   }
   show(count);
10. 10.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Aman", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Meera (b) Hi, Arjun (c) Hi, Aman
11. 11.🔁 What does a loop do? (a) saves photos (b) repeats code (c) draws icons (d) deletes code
12. 12.🔁 What number does this code show?
    let scores = [80, 85, 11, 99];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
13. 13.🔁 What number does this code show?
    let scores = [2, 11, 12, 6];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
14. 14.🔁 What number does this code show?
    let runs = [5, 17, 13];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
15. 15.🔁 What number does this code show?
    let runs = [11, 77, 32];
    let count = 0;
    for (let i = 0; i < runs.length; i++) {
      if (runs[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
16. 16.🔁 What number does this code show?
    let runs = [18, 2, 3];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
17. 17.🔁 What number does this code show?
    let scores = [14, 7, 13];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
18. 18.🔁 list.length tells you ___. (a) the last item (b) how many items it has (c) the first item (d) the biggest item
19. 19.🔁 What number does this code show?
    let scores = [16, 43, 91];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 50) {
        count = count + 1;
      }
    }
    show(count);
20. 20.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Zoya", "Arjun", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Aman (b) Hi, Arjun (c) Hi, Riya (d) Hi, Zoya
21. 21.🔁 What number does this code show?
    let runs = [15, 18, 16];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
22. 22.🔁 What number does this code show?
    let steps = [3, 11, 12, 19];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
23. 23.🔁 What is the LAST line this code shows?
    let names = ["Kabir", "Aman", "Zoya", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Meera (b) Hi, Aman (c) Hi, Kabir (d) Hi, Zoya
24. 24.🔁 A loop over a list of 5 items runs its body how many times? (a) 6 (b) 4 (c) 5 (d) 1
25. 25.🔁 What is the LAST line this code shows?
    let names = ["Zoya", "Meera", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Meera (b) Hi, Arjun (c) Hi, Zoya
26. 26.🔁 What number does this code show?
    let steps = [20, 14, 9, 10, 14];
    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 marks = [10, 5, 16];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
28. 28.🔁 What number does this code show?
    let marks = [18, 18, 13, 14];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
29. 29.🔁 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
30. 30.🔁 What number does this code show?
    let scores = [2, 2, 20, 9];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
31. 31.🔁 What number does this code show?
    let marks = [12, 14, 13, 18, 5];
    let best = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] > best) {
        best = marks[i];
      }
    }
    show(best);
32. 32.🔁 What number does this code show?
    let scores = [2, 13, 8, 3, 7];
    let total = 0;
    for (let i = 0; i < scores.length; i++) {
      total = total + scores[i];
    }
    show(total);
33. 33.🔁 What number does this code show?
    let steps = [12, 6, 10, 17, 1];
    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 steps = [8, 3, 14];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
35. 35.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 0, 1, 2 (b) 1, 2, 3 (c) 3 (d) 0, 1, 2, 3
36. 36.🔁 What number does this code show?
    let steps = [94, 84, 54, 98];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
37. 37.🔁 What number does this code show?
    let marks = [15, 17, 20, 7];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
38. 38.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Arjun", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Arjun (b) Hi, Riya (c) Hi, Meera
39. 39.🔁 What number does this code show?
    let runs = [15, 1, 17, 2];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
40. 40.🔁 What number does this code show?
    let scores = [29, 37, 26, 46, 27];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 70) {
        count = count + 1;
      }
    }
    show(count);

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