App Dev Worksheet: Loops over Lists
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
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1.🔁 What number does this code show?
let steps = [8, 4, 19];
let best = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] > best) {
best = steps[i];
}
}
show(best); -
2.🔁 What number does this code show?
let steps = [2, 16, 2, 11, 11];
let best = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] > best) {
best = steps[i];
}
}
show(best); -
3.🔁 What is the LAST line this code shows?
let names = ["Aman", "Kabir", "Arjun", "Meera", "Riya"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Arjun (b) Hi, Aman (c) Hi, Kabir (d) Hi, Riya -
4.🔁 What number does this code show?
let scores = [7, 5, 4, 2, 12];
let best = 0;
for (let i = 0; i < scores.length; i++) {
if (scores[i] > best) {
best = scores[i];
}
}
show(best); -
5.🔁 What number does this code show?
let steps = [3, 13, 4, 8, 18];
let best = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] > best) {
best = steps[i];
}
}
show(best); -
6.🔁 What number does this code show?
let runs = [9, 4, 16, 6, 1];
let total = 0;
for (let i = 0; i < runs.length; i++) {
total = total + runs[i];
}
show(total); -
7.🔁 What number does this code show?
let steps = [86, 72, 28, 15, 83];
let count = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] >= 40) {
count = count + 1;
}
}
show(count); - 8.🔁 A loop over a list of 5 items runs its body how many times? (a) 5 (b) 1 (c) 6 (d) 4
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9.🔁 What is the LAST line this code shows?
let names = ["Riya", "Kabir", "Zoya", "Aman", "Arjun"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Kabir (b) Hi, Zoya (c) Hi, Arjun (d) Hi, Riya -
10.🔁 What number does this code show?
let marks = [20, 14, 18, 10];
let total = 0;
for (let i = 0; i < marks.length; i++) {
total = total + marks[i];
}
show(total); -
11.🔁 What number does this code show?
let steps = [35, 20, 48, 78, 67];
let count = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] >= 40) {
count = count + 1;
}
}
show(count); -
12.🔁 What number does this code show?
let runs = [10, 18, 11];
let total = 0;
for (let i = 0; i < runs.length; i++) {
total = total + runs[i];
}
show(total); - 13.🔁 In for (let i = 0; i < 3; i++), which values does i take? (a) 3 (b) 1, 2, 3 (c) 0, 1, 2, 3 (d) 0, 1, 2
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14.🔁 What number does this code show?
let runs = [8, 10, 14, 19, 15];
let total = 0;
for (let i = 0; i < runs.length; i++) {
total = total + runs[i];
}
show(total); -
15.🔁 What number does this code show?
let marks = [2, 2, 2, 11];
let total = 0;
for (let i = 0; i < marks.length; i++) {
total = total + marks[i];
}
show(total); -
16.🔁 What number does this code show?
let steps = [1, 10, 3, 19];
let total = 0;
for (let i = 0; i < steps.length; i++) {
total = total + steps[i];
}
show(total); - 17.🔁 list.length tells you ___. (a) how many items it has (b) the biggest item (c) the first item (d) the last item
- 18.🔁 Why use a loop to show 100 messages? (a) it is slower (b) it hides them (c) less code to write (d) it uses more lines
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19.🔁 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, Meera (b) Hi, Riya (c) Hi, Arjun -
20.🔁 What number does this code show?
let steps = [12, 26, 58, 26, 42];
let count = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] >= 70) {
count = count + 1;
}
}
show(count); -
21.🔁 What is the LAST line this code shows?
let names = ["Arjun", "Aman", "Riya", "Meera", "Kabir"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Aman (b) Hi, Arjun (c) Hi, Riya (d) Hi, Kabir -
22.🔁 What is the LAST line this code shows?
let names = ["Kabir", "Arjun", "Meera", "Aman"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Aman (b) Hi, Arjun (c) Hi, Kabir (d) Hi, Meera -
23.🔁 What number does this code show?
let scores = [11, 13, 20, 7, 10];
let best = 0;
for (let i = 0; i < scores.length; i++) {
if (scores[i] > best) {
best = scores[i];
}
}
show(best); -
24.🔁 What number does this code show?
let marks = [1, 8, 18, 14, 8];
let best = 0;
for (let i = 0; i < marks.length; i++) {
if (marks[i] > best) {
best = marks[i];
}
}
show(best); -
25.🔁 What number does this code show?
let steps = [3, 2, 7];
let total = 0;
for (let i = 0; i < steps.length; i++) {
total = total + steps[i];
}
show(total); -
26.🔁 What number does this code show?
let scores = [4, 8, 9, 7];
let total = 0;
for (let i = 0; i < scores.length; i++) {
total = total + scores[i];
}
show(total); -
27.🔁 What is the LAST line this code shows?
let names = ["Kabir", "Meera", "Riya", "Zoya"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Kabir (b) Hi, Zoya (c) Hi, Riya (d) Hi, Meera -
28.🔁 What number does this code show?
let runs = [5, 11, 14, 2, 14];
let total = 0;
for (let i = 0; i < runs.length; i++) {
total = total + runs[i];
}
show(total); -
29.🔁 What number does this code show?
let steps = [78, 15, 80];
let count = 0;
for (let i = 0; i < steps.length; i++) {
if (steps[i] >= 40) {
count = count + 1;
}
}
show(count); -
30.🔁 What is the LAST line this code shows?
let names = ["Kabir", "Aman", "Arjun"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Kabir (b) Hi, Aman (c) Hi, Arjun -
31.🔁 What number does this code show?
let steps = [9, 4, 14, 14, 8];
let total = 0;
for (let i = 0; i < steps.length; i++) {
total = total + steps[i];
}
show(total); -
32.🔁 What number does this code show?
let steps = [11, 9, 8];
let total = 0;
for (let i = 0; i < steps.length; i++) {
total = total + steps[i];
}
show(total); -
33.🔁 What number does this code show?
let runs = [5, 2, 13, 9];
let total = 0;
for (let i = 0; i < runs.length; i++) {
total = total + runs[i];
}
show(total); - 34.🔁 What does a loop do? (a) repeats code (b) saves photos (c) draws icons (d) deletes code
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35.🔁 What is the LAST line this code shows?
let names = ["Meera", "Arjun", "Aman"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Arjun (b) Hi, Meera (c) Hi, Aman -
36.🔁 What number does this code show?
let marks = [31, 54, 82];
let count = 0;
for (let i = 0; i < marks.length; i++) {
if (marks[i] >= 60) {
count = count + 1;
}
}
show(count); -
37.🔁 What is the LAST line this code shows?
let names = ["Aman", "Arjun", "Meera", "Zoya"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Arjun (b) Hi, Zoya (c) Hi, Aman (d) Hi, Meera -
38.🔁 What is the LAST line this code shows?
let names = ["Riya", "Aman", "Arjun", "Kabir"];
for (let i = 0; i < names.length; i++) {
show("Hi, " + names[i]);
} (a) Hi, Aman (b) Hi, Arjun (c) Hi, Kabir (d) Hi, Riya -
39.🔁 What number does this code show?
let steps = [11, 14, 12, 18];
let total = 0;
for (let i = 0; i < steps.length; i++) {
total = total + steps[i];
}
show(total); -
40.🔁 What number does this code show?
let steps = [12, 6, 10, 13];
let total = 0;
for (let i = 0; i < steps.length; i++) {
total = total + steps[i];
}
show(total);
Answer key
- 19
- 16
- Hi, Riya
- 12
- 18
- 36
- 3
- 5
- Hi, Arjun
- 62
- 3
- 39
- 0, 1, 2
- 66
- 17
- 33
- how many items it has
- less code to write
- Hi, Meera
- 0
- Hi, Kabir
- Hi, Aman
- 20
- 18
- 12
- 28
- Hi, Zoya
- 46
- 2
- Hi, Arjun
- 49
- 28
- 29
- repeats code
- Hi, Aman
- 1
- Hi, Zoya
- Hi, Kabir
- 55
- 41
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