App Dev Worksheet: Variables, Lists and Saving

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

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