App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 83 · 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.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
2. 2.💾 What number does this code show?
   let songs = ["Sunrise", "Kites"];
   songs.push("Monsoon");
   songs.push("Stars");
   show(songs.length);
3. 3.💾 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
4. 4.💾 What number does this code show?
   let notes = ["Hindi", "Music", "Sports"];
   notes.push("Maths");
   show(notes.length);
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Art", "Music", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Music (c) Science (d) Art
6. 6.💾 What number does this code show?
   let notes = ["Hindi", "Maths", "Sports"];
   notes.push("Science");
   notes.push("Music");
   show(notes.length);
7. 7.💾 Which can hold many values in order? (a) a list (b) a single number (c) a button (d) a switch
8. 8.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) notes to read offline (d) a shared to-do list
9. 9.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 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
11. 11.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
12. 12.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
13. 13.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) photos on two devices (d) notes to read offline
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Meera", "Aman", "Kabir"];
    show(friends[3]); (a) Zoya (b) Aman (c) Meera (d) Arjun
15. 15.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Stars", "Sunrise"];
    show(songs[0]); (a) Sunrise (b) Rain (c) Stars
16. 16.💾 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
17. 17.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
18. 18.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) a shared chat (d) data saved on the phone
19. 19.💾 What number does this code show?
    let songs = ["Kites", "Ocean", "Rain"];
    songs.push("Sunrise");
    songs.push("Monsoon");
    show(songs.length);
20. 20.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Aman
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Riya", "Aman", "Arjun"];
    show(friends[3]); (a) Meera (b) Aman (c) Riya (d) Arjun
22. 22.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) a draft you are typing
23. 23.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Art", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Music (c) Art (d) Maths
24. 24.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Arjun", "Meera", "Riya", "Aman"];
    show(friends[1]); (a) Meera (b) Riya (c) Arjun (d) Kabir
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Aman", "Kabir", "Zoya"];
    show(friends[1]); (a) Aman (b) Kabir (c) Zoya (d) Meera
27. 27.💾 What number does this code show?
    let friends = ["Arjun", "Aman", "Kabir", "Meera"];
    friends.push("Zoya");
    show(friends.length);
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Hindi (d) Music
29. 29.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) a class leaderboard (d) a shared to-do list
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Science", "Music"];
    show(notes[1]); (a) Music (b) Art (c) Science
31. 31.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) your last game level (d) the sound on/off setting
32. 32.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
33. 33.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Hindi", "Science"];
    show(notes[1]); (a) Maths (b) Science (c) Art (d) Hindi
35. 35.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 1;
    show(score);
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Monsoon
37. 37.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 5;
    show(stars);
38. 38.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) the sound on/off setting (d) photos on two devices
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Kabir", "Riya", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Meera (d) Kabir
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Science", "Music", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Art (c) Science (d) Hindi

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