App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 509 · 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 = ["Aman", "Zoya"];
   friends.push("Riya");
   show(friends.length);
2. 2.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
3. 3.💾 What number does this code show?
   let friends = ["Meera", "Riya"];
   friends.push("Kabir");
   friends.push("Arjun");
   show(friends.length);
4. 4.💾 What number does this code show?
   let notes = ["Sports", "Science", "Music", "Art"];
   notes.push("Maths");
   show(notes.length);
5. 5.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Art", "Maths", "Hindi", "Sports"];
   show(notes[0]); (a) Hindi (b) Maths (c) Art (d) Science
7. 7.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) chat messages to friends (d) a class leaderboard
9. 9.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Music", "Science", "Hindi"];
    show(notes[0]); (a) Music (b) Sports (c) Art (d) Science
11. 11.💾 What number does this code show?
    let notes = ["Art", "Music", "Sports"];
    notes.push("Hindi");
    show(notes.length);
12. 12.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
13. 13.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
14. 14.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) a shared to-do list (d) photos on two devices
15. 15.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
17. 17.💾 What number does this code show?
    let notes = ["Art", "Music", "Maths"];
    notes.push("Science");
    notes.push("Sports");
    show(notes.length);
18. 18.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) the sound on/off setting (d) your last game level
19. 19.True or false: your last game level fits saving on the phone. (a) True (b) False
20. 20.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Zoya
22. 22.💾 What number does this code show?
    let notes = ["Music", "Sports", "Hindi"];
    notes.push("Maths");
    notes.push("Science");
    show(notes.length);
23. 23.💾 What number does this code show?
    let stars = 6;
    stars = stars - 3;
    stars = stars + 2;
    show(stars);
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Stars"];
    show(songs[0]); (a) Sunrise (b) Stars (c) Rain
25. 25.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
26. 26.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
27. 27.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
28. 28.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) a draft you are typing (d) notes to read offline
29. 29.💾 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
30. 30.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 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
32. 32.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
33. 33.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
34. 34.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a shared to-do list (d) photos on two devices
35. 35.💾 What number does this code show?
    let score = 5;
    score = score - 2;
    score = score + 1;
    show(score);
36. 36.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) notes to read offline (d) a class leaderboard
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Sports", "Art"];
    show(notes[2]); (a) Music (b) Maths (c) Sports (d) Art
38. 38.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) you send a message (d) the screen turns off
39. 39.💾 What number does this code show?
    let score = 9;
    score = score - 3;
    score = score + 5;
    show(score);
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Meera", "Aman", "Kabir", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Zoya (d) Kabir

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