App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 47 · 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 = ["Maths", "Hindi"];
   notes.push("Art");
   notes.push("Science");
   show(notes.length);
2. 2.💾 What does this code show? (Positions start at 0.)
   let friends = ["Meera", "Arjun", "Riya", "Zoya", "Kabir"];
   show(friends[4]); (a) Kabir (b) Riya (c) Arjun (d) Meera
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Monsoon", "Rain"];
   show(songs[0]); (a) Ocean (b) Monsoon (c) Rain
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Maths", "Hindi", "Sports"];
   show(notes[0]); (a) Music (b) Hindi (c) Maths (d) Sports
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the app is closed (d) the phone is lost
7. 7.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
8. 8.True or false: photos on two devices fits saving on the phone. (a) False (b) True
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) photos on two devices (d) a class leaderboard
10. 10.💾 What number does this code show?
    let notes = ["Art", "Science"];
    notes.push("Music");
    show(notes.length);
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) a draft you are typing (d) the sound on/off setting
13. 13.💾 What number does this code show?
    let notes = ["Maths", "Hindi", "Sports"];
    notes.push("Art");
    show(notes.length);
14. 14.💾 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
15. 15.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) notes to read offline (d) your last game level
16. 16.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
17. 17.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 3;
    show(score);
18. 18.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 3;
    show(coins);
19. 19.True or false: your last game level fits saving on the phone. (a) True (b) False
20. 20.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
21. 21.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir"];
    show(friends[0]); (a) Kabir (b) Zoya (c) Riya
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Music", "Hindi", "Art"];
    show(notes[3]); (a) Sports (b) Hindi (c) Maths (d) Music
24. 24.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
25. 25.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
28. 28.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
29. 29.💾 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
30. 30.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 What number does this code show?
    let coins = 7;
    coins = coins - 1;
    coins = coins + 3;
    show(coins);
32. 32.💾 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
33. 33.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Kabir");
    show(friends.length);
34. 34.💾 What is a variable? (a) a picture (b) a type of screen (c) a phone setting (d) a named box for a value
35. 35.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Music"];
    show(notes[2]); (a) Music (b) Science (c) Maths
37. 37.Which of these fits saving in the cloud? (a) notes to read offline (b) a class leaderboard (c) a draft you are typing (d) your last game level
38. 38.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) a cloud backup (d) data saved on the phone
39. 39.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 1;
    show(lives);
40. 40.💾 Which can hold many values in order? (a) a button (b) a switch (c) a single number (d) a list

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