App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 971 · 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 friends = ["Arjun", "Zoya", "Riya"];
   friends.push("Meera");
   friends.push("Kabir");
   show(friends.length);
2. 2.True or false: notes to read offline fits saving on the phone. (a) True (b) False
3. 3.💾 What number does this code show?
   let coins = 7;
   coins = coins - 5;
   coins = coins + 1;
   show(coins);
4. 4.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) the sound on/off setting (d) a class leaderboard
5. 5.True or false: photos on two devices fits saving on the phone. (a) True (b) False
6. 6.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
7. 7.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) the screen turns off (d) you send a message
8. 8.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
9. 9.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) chat messages to friends
11. 11.Which of these fits saving on the phone? (a) chat messages to friends (b) your last game level (c) a class leaderboard (d) photos on two devices
12. 12.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
13. 13.💾 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
14. 14.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Ocean"];
    songs.push("Monsoon");
    songs.push("Kites");
    show(songs.length);
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Maths", "Hindi"];
    show(notes[2]); (a) Science (b) Sports (c) Hindi (d) Maths
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Music", "Hindi", "Maths"];
    show(notes[0]); (a) Art (b) Science (c) Hindi (d) Music
17. 17.💾 What number does this code show?
    let stars = 4;
    stars = stars - 4;
    stars = stars + 5;
    show(stars);
18. 18.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Arjun", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Arjun (c) Riya
19. 19.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Kites", "Ocean"];
    show(songs[0]); (a) Sunrise (b) Kites (c) Rain (d) Ocean
20. 20.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
21. 21.💾 Which can hold many values in order? (a) a button (b) a switch (c) a single number (d) a list
22. 22.💾 What number does this code show?
    let points = 6;
    points = points - 3;
    points = points + 4;
    show(points);
23. 23.True or false: your last game level fits saving on the phone. (a) False (b) True
24. 24.💾 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
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi
26. 26.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) a shared to-do list (d) chat messages to friends
27. 27.💾 What number does this code show?
    let score = 9;
    score = score - 9;
    score = score + 4;
    show(score);
28. 28.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) your last game level (d) a shared to-do list
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Art", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Science (d) Art
30. 30.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Kabir (c) Riya
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Aman"];
    show(friends[0]); (a) Arjun (b) Aman (c) Riya
33. 33.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) use it on any device (c) never need a password (d) skip the internet
34. 34.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Aman", "Riya"];
    show(friends[2]); (a) Kabir (b) Aman (c) Riya
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Zoya", "Riya", "Kabir"];
    show(friends[0]); (a) Arjun (b) Zoya (c) Riya (d) Meera
36. 36.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Music", "Art", "Maths"];
    show(notes[1]); (a) Art (b) Science (c) Music (d) Sports
38. 38.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) the sound on/off setting (d) a draft you are typing
39. 39.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 2;
    show(lives);
40. 40.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) data saved on the phone (d) a cloud leaderboard

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