App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 59 · 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.💾 Which can hold many values in order? (a) a list (b) a switch (c) a single number (d) a button
2. 2.💾 What number does this code show?
   let lives = 5;
   lives = lives - 5;
   lives = lives + 1;
   show(lives);
3. 3.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
4. 4.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) chat messages to friends (d) a shared to-do list
5. 5.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) your last game level (d) a draft you are typing
6. 6.💾 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
7. 7.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Monsoon", "Ocean", "Rain"];
   show(songs[2]); (a) Monsoon (b) Stars (c) Rain (d) Ocean
8. 8.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
9. 9.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
10. 10.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 4;
    show(score);
11. 11.💾 What number does this code show?
    let notes = ["Music", "Hindi"];
    notes.push("Art");
    notes.push("Maths");
    show(notes.length);
12. 12.💾 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
13. 13.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) chat messages to friends (d) notes to read offline
14. 14.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Science", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Art (d) Sports
16. 16.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
17. 17.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) a class leaderboard (d) a shared to-do list
18. 18.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
19. 19.💾 What number does this code show?
    let lives = 9;
    lives = lives - 2;
    lives = lives + 1;
    show(lives);
20. 20.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) the sound on/off setting (d) notes to read offline
21. 21.💾 What number does this code show?
    let lives = 4;
    lives = lives - 1;
    lives = lives + 1;
    show(lives);
22. 22.Which of these fits saving in the cloud? (a) a class leaderboard (b) a draft you are typing (c) notes to read offline (d) the sound on/off setting
23. 23.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.True or false: your last game level fits saving in the cloud. (a) False (b) True
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Sports (c) Maths (d) Music
26. 26.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a cloud leaderboard (d) a shared chat
27. 27.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Hindi", "Science"];
    show(notes[1]); (a) Sports (b) Hindi (c) Science (d) Maths
28. 28.💾 What number does this code show?
    let lives = 7;
    lives = lives - 2;
    lives = lives + 4;
    show(lives);
29. 29.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 10 (d) 2
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Sunrise"];
    show(songs[1]); (a) Sunrise (b) Ocean (c) Rain
31. 31.Which of these fits saving on the phone? (a) notes to read offline (b) photos on two devices (c) a class leaderboard (d) chat messages to friends
32. 32.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What number does this code show?
    let notes = ["Science", "Maths"];
    notes.push("Music");
    show(notes.length);
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths", "Hindi", "Art"];
    show(notes[1]); (a) Hindi (b) Sports (c) Maths (d) Science
35. 35.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) the sound on/off setting (d) chat messages to friends
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Kabir
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Art"];
    show(notes[1]); (a) Maths (b) Science (c) Art
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Aman", "Zoya", "Kabir"];
    show(friends[4]); (a) Aman (b) Kabir (c) Arjun (d) Meera
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Sports"];
    show(notes[2]); (a) Sports (b) Music (c) Hindi
40. 40.True or false: chat messages to friends fits saving on the phone. (a) False (b) True

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