App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 522 · 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 notes = ["Science", "Sports", "Art"];
   notes.push("Maths");
   notes.push("Music");
   show(notes.length);
2. 2.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) notes to read offline (d) photos on two devices
3. 3.💾 Which can hold many values in order? (a) a button (b) a single number (c) a switch (d) a list
4. 4.💾 What number does this code show?
   let coins = 8;
   coins = coins - 1;
   coins = coins + 1;
   show(coins);
5. 5.💾 What number does this code show?
   let notes = ["Science", "Music", "Sports"];
   notes.push("Art");
   notes.push("Maths");
   show(notes.length);
6. 6.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
7. 7.💾 What number does this code show?
   let notes = ["Music", "Sports"];
   notes.push("Maths");
   notes.push("Hindi");
   show(notes.length);
8. 8.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) a shared to-do list (d) the sound on/off setting
9. 9.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 What number does this code show?
    let stars = 6;
    stars = stars - 2;
    stars = stars + 2;
    show(stars);
11. 11.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.💾 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
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Stars
14. 14.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
15. 15.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a draft you are typing (d) a shared to-do list
16. 16.💾 What number does this code show?
    let stars = 9;
    stars = stars - 7;
    stars = stars + 2;
    show(stars);
17. 17.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Monsoon", "Kites", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Monsoon (d) Kites
18. 18.💾 What number does this code show?
    let notes = ["Music", "Art", "Sports"];
    notes.push("Maths");
    notes.push("Hindi");
    show(notes.length);
19. 19.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 5;
    show(score);
20. 20.💾 What number does this code show?
    let lives = 6;
    lives = lives - 1;
    lives = lives + 4;
    show(lives);
21. 21.💾 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
22. 22.True or false: notes to read offline fits saving on the phone. (a) False (b) True
23. 23.💾 What number does this code show?
    let coins = 4;
    coins = coins - 3;
    coins = coins + 4;
    show(coins);
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Zoya", "Kabir", "Riya", "Meera"];
    show(friends[4]); (a) Kabir (b) Aman (c) Meera (d) Zoya
25. 25.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art"];
    show(notes[1]); (a) Maths (b) Art (c) Music
27. 27.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths", "Art"];
    show(notes[3]); (a) Sports (b) Science (c) Art (d) Maths
29. 29.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Science", "Maths"];
    show(notes[0]); (a) Hindi (b) Art (c) Maths (d) Science
31. 31.Which of these fits saving in the cloud? (a) a shared to-do list (b) a draft you are typing (c) notes to read offline (d) your last game level
32. 32.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What number does this code show?
    let notes = ["Art", "Music", "Science"];
    notes.push("Maths");
    notes.push("Sports");
    show(notes.length);
34. 34.True or false: your last game level fits saving on the phone. (a) False (b) True
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Kabir", "Arjun"];
    show(friends[2]); (a) Zoya (b) Arjun (c) Kabir
36. 36.💾 What number does this code show?
    let songs = ["Rain", "Sunrise"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
37. 37.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
38. 38.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) notes to read offline (d) a draft you are typing
39. 39.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Aman", "Arjun"];
    show(friends[2]); (a) Aman (b) Zoya (c) Arjun

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