App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 620 · 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.True or false: notes to read offline fits saving on the phone. (a) True (b) False
2. 2.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.💾 What number does this code show?
   let coins = 5;
   coins = coins - 2;
   coins = coins + 4;
   show(coins);
4. 4.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Kites", "Sunrise", "Ocean", "Stars"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Rain (d) Kites
5. 5.💾 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
6. 6.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Kabir", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Kabir
7. 7.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Rain", "Monsoon", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Monsoon (d) Stars
10. 10.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
11. 11.💾 What number does this code show?
    let notes = ["Sports", "Music", "Maths", "Science"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
12. 12.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
13. 13.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
14. 14.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 10 (d) 1
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Music", "Science"];
    show(notes[3]); (a) Music (b) Maths (c) Science (d) Art
16. 16.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) photos on two devices (d) a class leaderboard
17. 17.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Meera
18. 18.💾 What number does this code show?
    let notes = ["Maths", "Science"];
    notes.push("Sports");
    show(notes.length);
19. 19.True or false: your last game level fits saving on the phone. (a) False (b) True
20. 20.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Music", "Hindi"];
    show(notes[3]); (a) Music (b) Art (c) Hindi (d) Maths
21. 21.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
22. 22.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Rain", "Ocean", "Stars"];
    show(songs[4]); (a) Sunrise (b) Kites (c) Rain (d) Stars
23. 23.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) a draft you are typing (d) notes to read offline
24. 24.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya
25. 25.True or false: your last game level fits saving in the cloud. (a) True (b) False
26. 26.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a cloud leaderboard (d) a shared chat
27. 27.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.Which of these fits saving on the phone? (a) a shared to-do list (b) notes to read offline (c) photos on two devices (d) chat messages to friends
30. 30.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
31. 31.💾 What number does this code show?
    let coins = 6;
    coins = coins - 6;
    coins = coins + 4;
    show(coins);
32. 32.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 2;
    show(score);
33. 33.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
34. 34.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) skip the internet (d) shrink the app
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Aman", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Kabir
36. 36.💾 What number does this code show?
    let stars = 8;
    stars = stars - 1;
    stars = stars + 4;
    show(stars);
37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Monsoon", "Sunrise", "Stars", "Rain"];
    show(songs[2]); (a) Stars (b) Ocean (c) Sunrise (d) Monsoon
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art", "Sports", "Hindi"];
    show(notes[4]); (a) Art (b) Music (c) Maths (d) Hindi
39. 39.💾 What number does this code show?
    let stars = 4;
    stars = stars - 1;
    stars = stars + 2;
    show(stars);
40. 40.💾 What number does this code show?
    let notes = ["Maths", "Sports"];
    notes.push("Music");
    show(notes.length);

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