App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 203 · 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.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
2. 2.💾 What number does this code show?
   let friends = ["Riya", "Aman"];
   friends.push("Kabir");
   show(friends.length);
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Sunrise", "Kites", "Rain", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Kites (d) Sunrise
4. 4.💾 Which can hold many values in order? (a) a single number (b) a button (c) a list (d) a switch
5. 5.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
6. 6.💾 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
7. 7.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
8. 8.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Rain", "Stars", "Sunrise"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Stars (b) Rain (c) Kites (d) Sunrise
9. 9.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) shrink the app (d) never need a password
10. 10.True or false: your last game level fits saving on the phone. (a) False (b) True
11. 11.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) the sound on/off setting (d) chat messages to friends
12. 12.Which of these fits saving on the phone? (a) photos on two devices (b) your last game level (c) a class leaderboard (d) a shared to-do list
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi
14. 14.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Ocean", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Kites (d) Rain
17. 17.💾 What number does this code show?
    let lives = 9;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
18. 18.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
19. 19.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) your last game level (d) a draft you are typing
21. 21.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Hindi", "Sports", "Art", "Music"];
    show(notes[2]); (a) Art (b) Maths (c) Hindi (d) Sports
23. 23.💾 What number does this code show?
    let score = 5;
    score = score - 2;
    score = score + 4;
    show(score);
24. 24.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a shared to-do list (d) a draft you are typing
25. 25.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Rain", "Sunrise", "Kites"];
    show(songs[1]); (a) Sunrise (b) Kites (c) Rain (d) Ocean
26. 26.💾 What number does this code show?
    let notes = ["Sports", "Art"];
    notes.push("Hindi");
    show(notes.length);
27. 27.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 3;
    show(points);
28. 28.💾 What number does this code show?
    let songs = ["Rain", "Ocean", "Sunrise", "Kites"];
    songs.push("Monsoon");
    songs.push("Stars");
    show(songs.length);
29. 29.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
30. 30.💾 What number does this code show?
    let points = 8;
    points = points - 8;
    points = points + 2;
    show(points);
31. 31.💾 What number does this code show?
    let notes = ["Science", "Hindi", "Sports"];
    notes.push("Maths");
    show(notes.length);
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Kabir", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Zoya (d) Kabir
33. 33.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a class leaderboard (d) the sound on/off setting
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
36. 36.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
38. 38.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
39. 39.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 1;
    show(lives);
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Aman", "Meera", "Riya"];
    show(friends[3]); (a) Zoya (b) Aman (c) Kabir (d) Meera

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