App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 372 · 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 lives = 4;
   lives = lives - 4;
   lives = lives + 1;
   show(lives);
2. 2.💾 What number does this code show?
   let notes = ["Science", "Hindi"];
   notes.push("Music");
   show(notes.length);
3. 3.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
4. 4.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a named box for a value (d) a picture
5. 5.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a class leaderboard (d) a draft you are typing
6. 6.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
7. 7.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Monsoon", "Ocean", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Stars (d) Ocean
8. 8.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a list (d) a button
9. 9.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
10. 10.💾 What number does this code show?
    let stars = 5;
    stars = stars - 3;
    stars = stars + 3;
    show(stars);
11. 11.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud backup (d) a cloud leaderboard
12. 12.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Sports", "Music", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Music (d) Hindi
13. 13.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Meera"];
    show(friends[0]); (a) Riya (b) Arjun (c) Meera
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Hindi", "Sports"];
    show(notes[0]); (a) Art (b) Sports (c) Science (d) Hindi
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Music", "Hindi"];
    show(notes[0]); (a) Hindi (b) Music (c) Sports
17. 17.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Riya");
    show(friends.length);
18. 18.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) a draft you are typing (d) the sound on/off setting
19. 19.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) chat messages to friends (d) a class leaderboard
20. 20.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 5;
    show(score);
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Kabir", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Kabir
22. 22.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
23. 23.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Science");
    show(notes.length);
24. 24.💾 What number does this code show?
    let friends = ["Riya", "Aman"];
    friends.push("Meera");
    friends.push("Arjun");
    show(friends.length);
25. 25.💾 What number does this code show?
    let points = 9;
    points = points - 1;
    points = points + 1;
    show(points);
26. 26.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Hindi", "Art", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Science (d) Hindi
28. 28.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
29. 29.💾 What number does this code show?
    let score = 5;
    score = score - 4;
    score = score + 1;
    show(score);
30. 30.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) notes to read offline (d) a class leaderboard
31. 31.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Science", "Hindi", "Music"];
    show(notes[4]); (a) Sports (b) Art (c) Music (d) Science
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Hindi", "Art"];
    show(notes[3]); (a) Music (b) Art (c) Hindi (d) Maths
33. 33.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Maths", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Music (c) Sports (d) Art
35. 35.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
36. 36.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Kites");
    songs.push("Monsoon");
    show(songs.length);
37. 37.True or false: photos on two devices fits saving on the phone. (a) True (b) False
38. 38.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
39. 39.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 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

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