App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 129 · 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 a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.💾 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
3. 3.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) data saved on the phone (d) a cloud backup
4. 4.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
5. 5.💾 What number does this code show?
   let friends = ["Meera", "Arjun", "Aman", "Zoya"];
   friends.push("Kabir");
   show(friends.length);
6. 6.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
7. 7.True or false: photos on two devices fits saving on the phone. (a) True (b) False
8. 8.💾 What number does this code show?
   let stars = 4;
   stars = stars - 1;
   stars = stars + 2;
   show(stars);
9. 9.💾 What number does this code show?
   let friends = ["Arjun", "Kabir", "Zoya"];
   friends.push("Aman");
   friends.push("Meera");
   show(friends.length);
10. 10.💾 What number does this code show?
    let notes = ["Art", "Maths"];
    notes.push("Music");
    notes.push("Science");
    show(notes.length);
11. 11.💾 What number does this code show?
    let notes = ["Maths", "Art", "Sports", "Music"];
    notes.push("Hindi");
    show(notes.length);
12. 12.💾 What number does this code show?
    let notes = ["Maths", "Music", "Sports"];
    notes.push("Art");
    notes.push("Science");
    show(notes.length);
13. 13.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
14. 14.💾 What number does this code show?
    let coins = 3;
    coins = coins - 2;
    coins = coins + 5;
    show(coins);
15. 15.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) your last game level (d) a draft you are typing
16. 16.💾 Which can hold many values in order? (a) a button (b) a switch (c) a single number (d) a list
17. 17.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Science", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Sports (c) Music (d) Maths
18. 18.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
20. 20.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Hindi", "Art", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Sports (c) Art (d) Hindi
21. 21.💾 What number does this code show?
    let songs = ["Stars", "Ocean", "Kites", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
22. 22.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
23. 23.💾 What number does this code show?
    let lives = 5;
    lives = lives - 4;
    lives = lives + 1;
    show(lives);
24. 24.💾 What number does this code show?
    let friends = ["Zoya", "Kabir", "Arjun"];
    friends.push("Meera");
    show(friends.length);
25. 25.💾 What number does this code show?
    let notes = ["Sports", "Science"];
    notes.push("Maths");
    show(notes.length);
26. 26.💾 What number does this code show?
    let notes = ["Art", "Maths"];
    notes.push("Music");
    show(notes.length);
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Stars"];
    show(songs[0]); (a) Stars (b) Rain (c) Kites
28. 28.💾 What number does this code show?
    let songs = ["Ocean", "Stars", "Kites"];
    songs.push("Rain");
    songs.push("Monsoon");
    show(songs.length);
29. 29.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
30. 30.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) the sound on/off setting (d) photos on two devices
31. 31.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) a shared to-do list (d) chat messages to friends
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Meera (d) Kabir
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Riya", "Aman", "Arjun"];
    show(friends[0]); (a) Riya (b) Aman (c) Kabir (d) Meera
34. 34.True or false: your last game level fits saving on the phone. (a) True (b) False
35. 35.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
36. 36.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Riya (c) Arjun
38. 38.💾 What number does this code show?
    let lives = 7;
    lives = lives - 5;
    lives = lives + 3;
    show(lives);
39. 39.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) the sound on/off setting (d) a shared to-do list
40. 40.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost

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