App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 823 · 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", "Kabir", "Riya", "Meera"];
   friends.push("Zoya");
   show(friends.length);
2. 2.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
3. 3.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
4. 4.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) chat messages to friends (d) the sound on/off setting
5. 5.💾 What number does this code show?
   let score = 3;
   score = score - 1;
   score = score + 4;
   show(score);
6. 6.True or false: notes to read offline fits saving on the phone. (a) False (b) True
7. 7.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
8. 8.💾 What number does this code show?
   let friends = ["Kabir", "Zoya", "Aman", "Riya"];
   friends.push("Arjun");
   show(friends.length);
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Hindi", "Music", "Science"];
   show(notes[2]); (a) Science (b) Hindi (c) Music
10. 10.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) chat messages to friends (d) your last game level
11. 11.💾 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
12. 12.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let points = 6;
    points = points - 5;
    points = points + 3;
    show(points);
14. 14.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Art", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Science (d) Music
16. 16.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a shared to-do list (d) a draft you are typing
17. 17.💾 What number does this code show?
    let friends = ["Zoya", "Meera", "Aman"];
    friends.push("Riya");
    friends.push("Arjun");
    show(friends.length);
18. 18.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 2;
    show(coins);
19. 19.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
20. 20.Which of these fits saving in the cloud? (a) photos on two devices (b) a draft you are typing (c) your last game level (d) notes to read offline
21. 21.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.💾 What is a variable? (a) a type of screen (b) a named box for a value (c) a phone setting (d) a picture
23. 23.💾 What number does this code show?
    let coins = 9;
    coins = coins - 6;
    coins = coins + 2;
    show(coins);
24. 24.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Arjun"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
25. 25.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 2;
    show(coins);
26. 26.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Sunrise", "Kites"];
    show(songs[0]); (a) Sunrise (b) Kites (c) Ocean
27. 27.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the app is closed (d) the phone is lost
28. 28.💾 What number does this code show?
    let notes = ["Art", "Music", "Hindi"];
    notes.push("Maths");
    show(notes.length);
29. 29.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Ocean", "Rain"];
    show(songs[0]); (a) Rain (b) Ocean (c) Kites (d) Monsoon
31. 31.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
32. 32.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
33. 33.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) a class leaderboard (d) a shared to-do list
34. 34.True or false: photos on two devices fits saving on the phone. (a) False (b) True
35. 35.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Maths", "Sports", "Hindi", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Hindi (c) Science (d) Maths
36. 36.💾 What number does this code show?
    let lives = 8;
    lives = lives - 1;
    lives = lives + 4;
    show(lives);
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Meera", "Zoya", "Aman"];
    show(friends[2]); (a) Zoya (b) Kabir (c) Riya (d) Meera
38. 38.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
39. 39.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Sports", "Art"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
40. 40.💾 Which can hold many values in order? (a) a switch (b) a list (c) a button (d) a single number

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