App Dev Worksheet: Loops over Lists

App development lesson 19: Loops over lists · Set 517 · 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 = ["Aman", "Zoya", "Meera", "Arjun"];
   for (let i = 0; i < names.length; i++) {
     show("Hi, " + names[i]);
   } (a) Hi, Aman (b) Hi, Zoya (c) Hi, Meera (d) Hi, Arjun
2. 2.🔁 What number does this code show?
   let steps = [3, 3, 12, 17, 16];
   let best = 0;
   for (let i = 0; i < steps.length; i++) {
     if (steps[i] > best) {
       best = steps[i];
     }
   }
   show(best);
3. 3.🔁 What number does this code show?
   let runs = [20, 81, 23];
   let count = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] >= 70) {
       count = count + 1;
     }
   }
   show(count);
4. 4.🔁 What number does this code show?
   let scores = [2, 10, 7];
   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 runs = [12, 2, 16];
   let best = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] > best) {
       best = runs[i];
     }
   }
   show(best);
6. 6.🔁 What number does this code show?
   let scores = [6, 8, 5];
   let total = 0;
   for (let i = 0; i < scores.length; i++) {
     total = total + scores[i];
   }
   show(total);
7. 7.🔁 What number does this code show?
   let steps = [5, 16, 12, 19, 16];
   let best = 0;
   for (let i = 0; i < steps.length; i++) {
     if (steps[i] > best) {
       best = steps[i];
     }
   }
   show(best);
8. 8.🔁 What number does this code show?
   let runs = [8, 4, 16, 4];
   let best = 0;
   for (let i = 0; i < runs.length; i++) {
     if (runs[i] > best) {
       best = runs[i];
     }
   }
   show(best);
9. 9.🔁 What number does this code show?
   let marks = [4, 18, 17, 15, 1];
   let total = 0;
   for (let i = 0; i < marks.length; i++) {
     total = total + marks[i];
   }
   show(total);
10. 10.🔁 A loop over a list of 5 items runs its body how many times? (a) 1 (b) 6 (c) 4 (d) 5
11. 11.🔁 What number does this code show?
    let marks = [14, 6, 6];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
12. 12.🔁 What number does this code show?
    let scores = [16, 15, 5];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
13. 13.🔁 What is the LAST line this code shows?
    let names = ["Zoya", "Meera", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Zoya (b) Hi, Aman (c) Hi, Meera
14. 14.🔁 Why use a loop to show 100 messages? (a) it hides them (b) it uses more lines (c) it is slower (d) less code to write
15. 15.🔁 What number does this code show?
    let marks = [8, 7, 8, 14, 10];
    let total = 0;
    for (let i = 0; i < marks.length; i++) {
      total = total + marks[i];
    }
    show(total);
16. 16.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Aman", "Kabir", "Zoya", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Aman (b) Hi, Riya (c) Hi, Arjun (d) Hi, Kabir
17. 17.🔁 What number does this code show?
    let runs = [1, 3, 19, 9];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
18. 18.🔁 What number does this code show?
    let scores = [7, 6, 12];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
19. 19.🔁 What number does this code show?
    let steps = [12, 11, 64];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
20. 20.🔁 What number does this code show?
    let steps = [18, 1, 17];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
21. 21.🔁 What number does this code show?
    let runs = [16, 3, 16];
    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 scores = [10, 11, 3];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
23. 23.🔁 What number does this code show?
    let steps = [10, 1, 9, 18];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
24. 24.🔁 What does a loop do? (a) draws icons (b) saves photos (c) deletes code (d) repeats code
25. 25.🔁 What is the LAST line this code shows?
    let names = ["Meera", "Zoya", "Aman", "Riya"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Riya (b) Hi, Zoya (c) Hi, Meera (d) Hi, Aman
26. 26.🔁 What is the LAST line this code shows?
    let names = ["Zoya", "Riya", "Meera"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Zoya (b) Hi, Riya (c) Hi, Meera
27. 27.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 1, 2, 3 (b) 0, 1, 2, 3 (c) 3 (d) 0, 1, 2
28. 28.🔁 What number does this code show?
    let scores = [16, 66, 16];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
29. 29.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Kabir", "Arjun", "Aman"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Kabir (b) Hi, Arjun (c) Hi, Aman (d) Hi, Riya
30. 30.🔁 What number does this code show?
    let runs = [13, 5, 11, 13, 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 runs = [5, 3, 10];
    let total = 0;
    for (let i = 0; i < runs.length; i++) {
      total = total + runs[i];
    }
    show(total);
32. 32.🔁 What number does this code show?
    let steps = [7, 9, 13, 10];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);
33. 33.🔁 list.length tells you ___. (a) the last item (b) the first item (c) the biggest item (d) how many items it has
34. 34.🔁 What is the LAST line this code shows?
    let names = ["Riya", "Aman", "Meera", "Kabir", "Arjun"];
    for (let i = 0; i < names.length; i++) {
      show("Hi, " + names[i]);
    } (a) Hi, Riya (b) Hi, Aman (c) Hi, Meera (d) Hi, Arjun
35. 35.🔁 What number does this code show?
    let steps = [42, 44, 69, 11];
    let count = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
36. 36.🔁 What number does this code show?
    let scores = [23, 50, 30];
    let count = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] >= 40) {
        count = count + 1;
      }
    }
    show(count);
37. 37.🔁 What number does this code show?
    let runs = [19, 10, 15, 15];
    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 = [6, 19, 4, 1, 20];
    let best = 0;
    for (let i = 0; i < scores.length; i++) {
      if (scores[i] > best) {
        best = scores[i];
      }
    }
    show(best);
39. 39.🔁 What number does this code show?
    let marks = [43, 52, 76, 81, 60];
    let count = 0;
    for (let i = 0; i < marks.length; i++) {
      if (marks[i] >= 60) {
        count = count + 1;
      }
    }
    show(count);
40. 40.🔁 What number does this code show?
    let steps = [9, 11, 14];
    let best = 0;
    for (let i = 0; i < steps.length; i++) {
      if (steps[i] > best) {
        best = steps[i];
      }
    }
    show(best);

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