App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 570 · 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 number does this code show?
   let coins = 5;
   coins = coins - 4;
   coins = coins + 1;
   show(coins);
2. 2.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 What number does this code show?
   let notes = ["Music", "Science", "Sports"];
   notes.push("Maths");
   show(notes.length);
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Sports", "Music"];
   show(notes[2]); (a) Sports (b) Music (c) Art
5. 5.True or false: notes to read offline fits saving on the phone. (a) True (b) False
6. 6.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
7. 7.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
8. 8.💾 What number does this code show?
   let notes = ["Science", "Sports"];
   notes.push("Maths");
   notes.push("Art");
   show(notes.length);
9. 9.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
10. 10.💾 What number does this code show?
    let friends = ["Kabir", "Riya", "Zoya"];
    friends.push("Arjun");
    show(friends.length);
11. 11.💾 What number does this code show?
    let friends = ["Arjun", "Aman", "Zoya"];
    friends.push("Riya");
    show(friends.length);
12. 12.💾 What number does this code show?
    let notes = ["Sports", "Art", "Music", "Maths"];
    notes.push("Hindi");
    show(notes.length);
13. 13.💾 What number does this code show?
    let coins = 8;
    coins = coins - 5;
    coins = coins + 5;
    show(coins);
14. 14.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) the sound on/off setting (d) notes to read offline
15. 15.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Art", "Music"];
    show(notes[0]); (a) Science (b) Music (c) Art (d) Hindi
17. 17.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a draft you are typing (d) a class leaderboard
18. 18.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) a cloud leaderboard (d) data saved on the phone
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Stars", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Monsoon (d) Stars
20. 20.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
21. 21.True or false: your last game level fits saving on the phone. (a) False (b) True
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Maths"];
    show(notes[1]); (a) Maths (b) Science (c) Music
23. 23.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Maths", "Hindi"];
    show(notes[3]); (a) Maths (b) Sports (c) Art (d) Hindi
25. 25.💾 What number does this code show?
    let friends = ["Kabir", "Meera"];
    friends.push("Zoya");
    friends.push("Aman");
    show(friends.length);
26. 26.💾 What number does this code show?
    let points = 3;
    points = points - 3;
    points = points + 1;
    show(points);
27. 27.💾 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) Music (c) Hindi
28. 28.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) the screen turns off (d) you send a message
29. 29.True or false: photos on two devices fits saving on the phone. (a) True (b) False
30. 30.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Arjun", "Riya"];
    show(friends[2]); (a) Meera (b) Kabir (c) Arjun (d) Riya
32. 32.💾 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
33. 33.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) notes to read offline (d) a class leaderboard
34. 34.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
35. 35.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) a class leaderboard (d) chat messages to friends
36. 36.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) the sound on/off setting (d) notes to read offline
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Music", "Sports", "Science"];
    show(notes[2]); (a) Hindi (b) Music (c) Art (d) Sports
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Music", "Art", "Science"];
    show(notes[4]); (a) Maths (b) Music (c) Science (d) Sports
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Sports (d) Music

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