App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 861 · 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 = ["Kabir", "Arjun", "Aman"];
   friends.push("Riya");
   show(friends.length);
2. 2.💾 What number does this code show?
   let songs = ["Kites", "Stars"];
   songs.push("Monsoon");
   show(songs.length);
3. 3.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 What number does this code show?
   let points = 4;
   points = points - 1;
   points = points + 3;
   show(points);
5. 5.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) the sound on/off setting (d) photos on two devices
6. 6.💾 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
7. 7.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
8. 8.💾 What number does this code show?
   let score = 4;
   score = score - 1;
   score = score + 5;
   show(score);
9. 9.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
10. 10.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 What number does this code show?
    let friends = ["Riya", "Kabir"];
    friends.push("Zoya");
    show(friends.length);
12. 12.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
13. 13.💾 What number does this code show?
    let lives = 7;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
14. 14.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Maths", "Sports"];
    show(notes[1]); (a) Music (b) Maths (c) Sports (d) Science
16. 16.💾 What number does this code show?
    let friends = ["Kabir", "Riya"];
    friends.push("Arjun");
    show(friends.length);
17. 17.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a shared chat (d) a cloud backup
18. 18.💾 What number does this code show?
    let notes = ["Music", "Maths", "Sports", "Art"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
19. 19.💾 What number does this code show?
    let songs = ["Ocean", "Stars", "Rain", "Sunrise"];
    songs.push("Kites");
    songs.push("Monsoon");
    show(songs.length);
20. 20.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
21. 21.Which of these fits saving on the phone? (a) a shared to-do list (b) notes to read offline (c) photos on two devices (d) chat messages to friends
22. 22.True or false: your last game level fits saving on the phone. (a) False (b) True
23. 23.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) photos on two devices (d) chat messages to friends
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir", "Meera"];
    show(friends[3]); (a) Riya (b) Zoya (c) Kabir (d) Meera
25. 25.💾 What number does this code show?
    let friends = ["Meera", "Aman"];
    friends.push("Arjun");
    show(friends.length);
26. 26.💾 What number does this code show?
    let notes = ["Science", "Hindi"];
    notes.push("Art");
    show(notes.length);
27. 27.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 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) Hindi (b) Music (c) Sports (d) Maths
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Arjun"];
    show(friends[0]); (a) Riya (b) Aman (c) Arjun
30. 30.💾 What is a variable? (a) a type of screen (b) a named box for a value (c) a picture (d) a phone setting
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Aman", "Kabir"];
    show(friends[1]); (a) Arjun (b) Kabir (c) Aman (d) Riya
32. 32.💾 What number does this code show?
    let songs = ["Ocean", "Monsoon"];
    songs.push("Stars");
    show(songs.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Music
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
36. 36.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
37. 37.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
38. 38.💾 What number does this code show?
    let notes = ["Music", "Sports"];
    notes.push("Science");
    notes.push("Art");
    show(notes.length);
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Art", "Maths", "Sports"];
    show(notes[1]); (a) Maths (b) Sports (c) Art (d) Hindi
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Aman", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Zoya (c) Kabir (d) Aman

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