App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 451 · 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 does this code show? (Positions start at 0.)
   let notes = ["Music", "Hindi", "Maths", "Sports", "Science"];
   show(notes[0]); (a) Hindi (b) Sports (c) Maths (d) Music
2. 2.💾 What number does this code show?
   let songs = ["Monsoon", "Sunrise"];
   songs.push("Rain");
   show(songs.length);
3. 3.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Aman", "Kabir", "Meera", "Zoya"];
   show(friends[4]); (a) Aman (b) Zoya (c) Kabir (d) Riya
4. 4.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Arjun", "Kabir"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Zoya
5. 5.💾 What number does this code show?
   let lives = 9;
   lives = lives - 8;
   lives = lives + 5;
   show(lives);
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
8. 8.💾 What does this code show? (Positions start at 0.)
   let notes = ["Hindi", "Maths", "Music"];
   show(notes[2]); (a) Hindi (b) Music (c) Maths
9. 9.💾 What number does this code show?
   let stars = 6;
   stars = stars - 1;
   stars = stars + 3;
   show(stars);
10. 10.💾 What number does this code show?
    let songs = ["Stars", "Rain", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
11. 11.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
13. 13.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a draft you are typing (d) a class leaderboard
14. 14.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
15. 15.True or false: your last game level fits saving on the phone. (a) True (b) False
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi
17. 17.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Maths
19. 19.💾 What number does this code show?
    let friends = ["Meera", "Zoya", "Arjun"];
    friends.push("Kabir");
    show(friends.length);
20. 20.💾 What number does this code show?
    let coins = 9;
    coins = coins - 5;
    coins = coins + 4;
    show(coins);
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Aman (d) Kabir
22. 22.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) notes to read offline (d) a class leaderboard
23. 23.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 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
25. 25.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) the sound on/off setting (d) photos on two devices
26. 26.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
27. 27.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a picture (d) a phone setting
28. 28.💾 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
29. 29.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a draft you are typing (d) a class leaderboard
30. 30.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
31. 31.💾 What number does this code show?
    let coins = 9;
    coins = coins - 6;
    coins = coins + 1;
    show(coins);
32. 32.💾 What number does this code show?
    let score = 9;
    score = score - 7;
    score = score + 3;
    show(score);
33. 33.💾 What number does this code show?
    let notes = ["Maths", "Science"];
    notes.push("Art");
    show(notes.length);
34. 34.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Zoya", "Riya", "Aman"];
    show(friends[0]); (a) Riya (b) Meera (c) Aman (d) Zoya
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Riya", "Aman"];
    show(friends[2]); (a) Meera (b) Riya (c) Aman
36. 36.💾 Which can hold many values in order? (a) a button (b) a list (c) a switch (d) a single number
37. 37.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
38. 38.💾 What number does this code show?
    let songs = ["Rain", "Kites"];
    songs.push("Ocean");
    songs.push("Sunrise");
    show(songs.length);
39. 39.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Ocean", "Rain", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Ocean (d) Stars
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Art", "Maths"];
    show(notes[2]); (a) Maths (b) Sports (c) Science (d) Art

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