App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 515 · 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 points = 7;
   points = points - 3;
   points = points + 3;
   show(points);
2. 2.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 10 (d) 0
3. 3.💾 What does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Riya", "Aman"];
   show(friends[1]); (a) Riya (b) Kabir (c) Aman
4. 4.💾 pop() takes off the last item. What does this code show?
   let friends = ["Kabir", "Zoya", "Riya", "Aman"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Riya (d) Kabir
5. 5.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 What number does this code show?
   let score = 9;
   score = score - 3;
   score = score + 3;
   show(score);
7. 7.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) your last game level (d) photos on two devices
10. 10.💾 What number does this code show?
    let friends = ["Aman", "Arjun", "Meera", "Kabir"];
    friends.push("Riya");
    friends.push("Zoya");
    show(friends.length);
11. 11.💾 What number does this code show?
    let notes = ["Science", "Sports"];
    notes.push("Art");
    notes.push("Maths");
    show(notes.length);
12. 12.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Kabir
13. 13.💾 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
14. 14.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) never need a password (c) shrink the app (d) skip the internet
15. 15.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
17. 17.True or false: your last game level fits saving on the phone. (a) True (b) False
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) chat messages to friends (d) notes to read offline
19. 19.💾 What number does this code show?
    let points = 8;
    points = points - 3;
    points = points + 1;
    show(points);
20. 20.True or false: your last game level fits saving in the cloud. (a) True (b) False
21. 21.💾 What number does this code show?
    let songs = ["Monsoon", "Ocean", "Kites", "Sunrise"];
    songs.push("Stars");
    songs.push("Rain");
    show(songs.length);
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Hindi"];
    show(notes[2]); (a) Art (b) Music (c) Hindi
23. 23.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
24. 24.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Zoya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Kabir (d) Aman
25. 25.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Maths", "Hindi", "Science"];
    show(notes[1]); (a) Maths (b) Music (c) Hindi (d) Art
27. 27.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Zoya (c) Aman
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Kabir", "Riya"];
    show(friends[0]); (a) Riya (b) Zoya (c) Kabir
30. 30.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Arjun", "Kabir"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
31. 31.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) photos on two devices (d) a class leaderboard
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Meera", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Meera
33. 33.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Sports"];
    notes.push("Maths");
    show(notes.length);
35. 35.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
36. 36.Which of these fits saving in the cloud? (a) chat messages to friends (b) your last game level (c) notes to read offline (d) the sound on/off setting
37. 37.💾 What number does this code show?
    let points = 6;
    points = points - 4;
    points = points + 3;
    show(points);
38. 38.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Kabir
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Science", "Art"];
    show(notes[1]); (a) Art (b) Maths (c) Science

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