App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 89 · 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.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Sports", "Hindi"];
   show(notes[2]); (a) Hindi (b) Sports (c) Art
2. 2.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) your last game level (d) the sound on/off setting
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Stars", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Stars (b) Monsoon (c) Rain
4. 4.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
5. 5.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
7. 7.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
8. 8.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Sunrise", "Rain", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Rain (d) Sunrise
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Art", "Hindi", "Sports"];
    show(notes[0]); (a) Maths (b) Art (c) Science (d) Hindi
11. 11.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
12. 12.Which of these fits saving on the phone? (a) a class leaderboard (b) the sound on/off setting (c) a shared to-do list (d) photos on two devices
13. 13.💾 Which can hold many values in order? (a) a button (b) a switch (c) a single number (d) a list
14. 14.💾 What number does this code show?
    let points = 5;
    points = points - 1;
    points = points + 4;
    show(points);
15. 15.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Science", "Hindi", "Sports"];
    show(notes[1]); (a) Maths (b) Hindi (c) Sports (d) Science
17. 17.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Music"];
    show(notes[0]); (a) Music (b) Sports (c) Art
18. 18.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Arjun", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Arjun (d) Zoya
19. 19.💾 What number does this code show?
    let notes = ["Science", "Maths"];
    notes.push("Music");
    show(notes.length);
20. 20.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Maths", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Maths (c) Hindi (d) Science
23. 23.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
24. 24.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Riya (d) Kabir
26. 26.💾 What number does this code show?
    let notes = ["Art", "Science", "Maths", "Sports"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
27. 27.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) a draft you are typing (d) notes to read offline
28. 28.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a shared to-do list (d) photos on two devices
29. 29.Which of these fits saving in the cloud? (a) a class leaderboard (b) notes to read offline (c) a draft you are typing (d) the sound on/off setting
30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Maths
31. 31.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Maths", "Sports"];
    show(notes[0]); (a) Hindi (b) Sports (c) Maths
32. 32.Which of these fits saving on the phone? (a) a draft you are typing (b) chat messages to friends (c) photos on two devices (d) a shared to-do list
33. 33.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
34. 34.💾 What number does this code show?
    let coins = 8;
    coins = coins - 3;
    coins = coins + 2;
    show(coins);
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Kites (c) Ocean (d) Sunrise
36. 36.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Aman", "Meera"];
    show(friends[2]); (a) Meera (b) Aman (c) Riya (d) Zoya
37. 37.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Zoya"];
    show(friends[2]); (a) Zoya (b) Arjun (c) Meera
39. 39.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Riya"];
    friends.push("Zoya");
    show(friends.length);
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Meera", "Zoya"];
    show(friends[0]); (a) Kabir (b) Zoya (c) Meera (d) Riya

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