App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 248 · 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.💾 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
2. 2.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
3. 3.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
4. 4.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Stars", "Monsoon", "Kites"];
   show(songs[2]); (a) Stars (b) Kites (c) Monsoon (d) Rain
5. 5.💾 What number does this code show?
   let notes = ["Maths", "Music"];
   notes.push("Sports");
   notes.push("Science");
   show(notes.length);
6. 6.💾 What number does this code show?
   let lives = 9;
   lives = lives - 1;
   lives = lives + 3;
   show(lives);
7. 7.💾 What number does this code show?
   let friends = ["Kabir", "Meera"];
   friends.push("Arjun");
   friends.push("Zoya");
   show(friends.length);
8. 8.💾 What number does this code show?
   let score = 7;
   score = score - 2;
   score = score + 3;
   show(score);
9. 9.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 0 (d) 10
11. 11.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 4;
    show(score);
12. 12.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) notes to read offline (d) your last game level
13. 13.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) the sound on/off setting (d) a draft you are typing
14. 14.💾 What number does this code show?
    let notes = ["Science", "Music", "Maths", "Hindi"];
    notes.push("Sports");
    notes.push("Art");
    show(notes.length);
15. 15.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
16. 16.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Kabir"];
    show(friends[0]); (a) Kabir (b) Meera (c) Aman
18. 18.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the phone is lost (d) the app is closed
19. 19.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Arjun"];
    friends.push("Kabir");
    show(friends.length);
20. 20.💾 What number does this code show?
    let notes = ["Art", "Music"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
21. 21.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Sunrise", "Ocean", "Kites", "Monsoon"];
    show(songs[4]); (a) Stars (b) Sunrise (c) Monsoon (d) Ocean
22. 22.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
23. 23.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
24. 24.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) photos on two devices (d) your last game level
25. 25.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 3;
    show(score);
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Zoya", "Aman"];
    show(friends[3]); (a) Meera (b) Kabir (c) Zoya (d) Aman
27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Meera (d) Kabir
28. 28.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
29. 29.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Zoya");
    show(friends.length);
31. 31.💾 What number does this code show?
    let lives = 4;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
32. 32.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a shared to-do list (d) the sound on/off setting
33. 33.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 5;
    show(coins);
34. 34.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Kites (c) Sunrise
35. 35.💾 What number does this code show?
    let points = 9;
    points = points - 1;
    points = points + 4;
    show(points);
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Sports", "Music"];
    show(notes[0]); (a) Sports (b) Maths (c) Music (d) Art
37. 37.True or false: notes to read offline fits saving on the phone. (a) False (b) True
38. 38.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a shared to-do list (d) a class leaderboard
39. 39.💾 What number does this code show?
    let notes = ["Science", "Maths", "Art"];
    notes.push("Music");
    show(notes.length);
40. 40.💾 What number does this code show?
    let notes = ["Sports", "Music", "Maths", "Art"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);

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