App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 30 · 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 is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
3. 3.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
4. 4.💾 What number does this code show?
   let lives = 4;
   lives = lives - 4;
   lives = lives + 1;
   show(lives);
5. 5.💾 What number does this code show?
   let songs = ["Rain", "Monsoon"];
   songs.push("Ocean");
   songs.push("Kites");
   show(songs.length);
6. 6.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
7. 7.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Maths", "Art", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Sports (c) Science (d) Art
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) the sound on/off setting
9. 9.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Meera", "Kabir"];
   show(friends[1]); (a) Zoya (b) Meera (c) Kabir
10. 10.True or false: notes to read offline fits saving on the phone. (a) True (b) False
11. 11.💾 What number does this code show?
    let stars = 8;
    stars = stars - 6;
    stars = stars + 3;
    show(stars);
12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Sunrise"];
    show(songs[0]); (a) Stars (b) Rain (c) Sunrise
13. 13.💾 What number does this code show?
    let notes = ["Maths", "Hindi", "Science", "Sports"];
    notes.push("Art");
    show(notes.length);
14. 14.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
15. 15.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) a shared to-do list (d) the sound on/off setting
16. 16.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
17. 17.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a cloud backup (d) a shared chat
18. 18.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
19. 19.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
20. 20.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Arjun", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Arjun (d) Riya
22. 22.True or false: your last game level fits saving on the phone. (a) True (b) False
23. 23.💾 What number does this code show?
    let coins = 5;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
24. 24.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Music (c) Maths (d) Art
25. 25.💾 What number does this code show?
    let notes = ["Hindi", "Art", "Science"];
    notes.push("Music");
    show(notes.length);
26. 26.💾 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
27. 27.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Hindi", "Science"];
    show(notes[1]); (a) Art (b) Music (c) Science (d) Hindi
29. 29.💾 What number does this code show?
    let stars = 9;
    stars = stars - 2;
    stars = stars + 4;
    show(stars);
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Sunrise"];
    show(songs[2]); (a) Monsoon (b) Sunrise (c) Stars
31. 31.💾 What number does this code show?
    let points = 9;
    points = points - 2;
    points = points + 3;
    show(points);
32. 32.💾 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
33. 33.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) notes to read offline (d) chat messages to friends
34. 34.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) a class leaderboard (d) a draft you are typing
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Arjun", "Meera", "Riya", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Arjun (c) Kabir (d) Riya
36. 36.Which of these fits saving on the phone? (a) a shared to-do list (b) a draft you are typing (c) photos on two devices (d) a class leaderboard
37. 37.💾 What number does this code show?
    let score = 5;
    score = score - 2;
    score = score + 4;
    show(score);
38. 38.💾 What number does this code show?
    let score = 5;
    score = score - 4;
    score = score + 5;
    show(score);
39. 39.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
40. 40.💾 What number does this code show?
    let score = 7;
    score = score - 2;
    score = score + 5;
    show(score);

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