App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 113 · 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.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a class leaderboard (d) photos on two devices
2. 2.True or false: notes to read offline fits saving on the phone. (a) False (b) True
3. 3.💾 What number does this code show?
   let notes = ["Art", "Music", "Maths"];
   notes.push("Hindi");
   show(notes.length);
4. 4.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
5. 5.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) chat messages to friends
6. 6.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) a class leaderboard (d) notes to read offline
7. 7.💾 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
8. 8.💾 What is a variable? (a) a picture (b) a named box for a value (c) a type of screen (d) a phone setting
9. 9.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.True or false: your last game level fits saving in the cloud. (a) True (b) False
11. 11.💾 What number does this code show?
    let songs = ["Monsoon", "Kites"];
    songs.push("Sunrise");
    show(songs.length);
12. 12.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
13. 13.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
14. 14.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) photos on two devices (d) notes to read offline
15. 15.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) a shared to-do list (d) a draft you are typing
16. 16.💾 What number does this code show?
    let friends = ["Aman", "Arjun", "Meera", "Riya"];
    friends.push("Kabir");
    friends.push("Zoya");
    show(friends.length);
17. 17.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Maths", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Science (c) Music (d) Sports
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Hindi"];
    show(notes[2]); (a) Hindi (b) Art (c) Sports
19. 19.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 3;
    show(score);
20. 20.💾 What number does this code show?
    let friends = ["Kabir", "Arjun"];
    friends.push("Riya");
    friends.push("Meera");
    show(friends.length);
21. 21.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Maths", "Art"];
    show(notes[0]); (a) Maths (b) Art (c) Hindi
22. 22.💾 What number does this code show?
    let notes = ["Science", "Hindi", "Music"];
    notes.push("Maths");
    notes.push("Art");
    show(notes.length);
23. 23.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Kabir (d) Aman
24. 24.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
25. 25.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
26. 26.💾 What number does this code show?
    let stars = 9;
    stars = stars - 8;
    stars = stars + 5;
    show(stars);
27. 27.💾 What number does this code show?
    let lives = 5;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
28. 28.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the app is closed (d) the screen turns off
29. 29.💾 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
30. 30.💾 What number does this code show?
    let stars = 8;
    stars = stars - 3;
    stars = stars + 2;
    show(stars);
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Monsoon"];
    show(songs[2]); (a) Rain (b) Monsoon (c) Ocean
32. 32.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What number does this code show?
    let lives = 6;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
34. 34.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
35. 35.💾 What number does this code show?
    let friends = ["Arjun", "Kabir", "Riya"];
    friends.push("Meera");
    show(friends.length);
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Meera (d) Zoya
37. 37.💾 What number does this code show?
    let notes = ["Art", "Sports", "Hindi"];
    notes.push("Maths");
    show(notes.length);
38. 38.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Kites"];
    show(songs[1]); (a) Kites (b) Monsoon (c) Sunrise
40. 40.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) skip the internet (d) use it on any device

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