App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 19 · 40 questions

Developer's tip (Box, list, place): A variable holds one value; a list holds many in order. Positions start at 0. push adds to the end; pop takes off the last item; length is how many items. On the phone: works offline, private. In the cloud: shared, any device, needs the internet.

1. 1.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Kabir", "Riya", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Meera (d) Riya
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Monsoon", "Ocean", "Rain"];
   show(songs[0]); (a) Rain (b) Monsoon (c) Stars (d) Ocean
3. 3.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
4. 4.💾 Which can hold many values in order? (a) a button (b) a single number (c) a switch (d) a list
5. 5.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
6. 6.💾 What number does this code show?
   let songs = ["Stars", "Ocean", "Rain"];
   songs.push("Kites");
   show(songs.length);
7. 7.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) the sound on/off setting
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Monsoon", "Rain", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Rain
10. 10.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
11. 11.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let points = 9;
    points = points - 1;
    points = points + 3;
    show(points);
14. 14.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a class leaderboard (d) a shared to-do list
15. 15.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.💾 What number does this code show?
    let notes = ["Music", "Art", "Science"];
    notes.push("Maths");
    show(notes.length);
18. 18.💾 What number does this code show?
    let friends = ["Meera", "Kabir", "Riya"];
    friends.push("Arjun");
    friends.push("Zoya");
    show(friends.length);
19. 19.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) a draft you are typing (d) the sound on/off setting
20. 20.💾 What number does this code show?
    let score = 5;
    score = score - 3;
    score = score + 2;
    show(score);
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Zoya (c) Arjun
22. 22.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
23. 23.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Sunrise", "Kites", "Rain"];
    show(songs[2]); (a) Monsoon (b) Stars (c) Kites (d) Sunrise
25. 25.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Art", "Science", "Maths"];
    show(notes[0]); (a) Maths (b) Science (c) Art (d) Hindi
27. 27.💾 What number does this code show?
    let stars = 8;
    stars = stars - 6;
    stars = stars + 2;
    show(stars);
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Science (c) Hindi
29. 29.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
30. 30.💾 What number does this code show?
    let lives = 7;
    lives = lives - 5;
    lives = lives + 3;
    show(lives);
31. 31.💾 What number does this code show?
    let friends = ["Meera", "Zoya", "Riya"];
    friends.push("Aman");
    friends.push("Kabir");
    show(friends.length);
32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Music
33. 33.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.True or false: notes to read offline fits saving on the phone. (a) True (b) False
35. 35.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
36. 36.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 2 (d) 10
37. 37.Which of these fits saving on the phone? (a) notes to read offline (b) photos on two devices (c) chat messages to friends (d) a class leaderboard
38. 38.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) use it on any device (d) never need a password
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Maths", "Hindi"];
    show(notes[0]); (a) Maths (b) Hindi (c) Sports (d) Art
40. 40.True or false: a draft you are typing fits saving on the phone. (a) False (b) True

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