App Dev Worksheet: Final Test

App development lesson 24: App development final test · Set 863 · 40 questions

Developer's tip (Plan, design, build, check): Find the topic: what apps are, designing apps, or logic and building. Read every screen, list or code line carefully, top to bottom. For code, write each value down step by step and check it again.

1. 1.🐞 Each comment says what its line SHOULD do. Which line has the bug?
   line 1: let stars = 39; // start at 36
   line 2: stars = stars + 6; // add 6
   line 3: stars = stars - 2; // take away 2
   line 4: show(stars); // show it (a) line 2 (b) line 3 (c) line 1
2. 2.🖼️ How many parts (boxes) does this wireframe have?
   [ top bar ]
   [ search box ]
   [ big picture ]
   [ menu icon ]
3. 3.🔁 What number does this code show?
   let steps = [42, 54, 99, 36];
   let count = 0;
   for (let i = 0; i < steps.length; i++) {
     if (steps[i] >= 70) {
       count = count + 1;
     }
   }
   show(count);
4. 4.✏️ Is this true of a wireframe or of a final design: looks like the real app? (a) a final design (b) a wireframe
5. 5.🗒️ Why keep version 1 small? (a) to use up storage (b) to look bigger (c) to confuse users (d) to learn from users soon
6. 6.🔀 In this course’s code, which sign tests “is equal to”? (a) = (b) === (c) !== (d) =>
7. 7.🧩 How many inputs (text boxes, switches and sliders) does this screen have?
   [title] Sign Up
   [text box] City
   [button] Cancel
   [text box] Subject
   [button] Next
   [text box] Age
8. 8.Which of these app ideas solves no real problem? (a) a page of random dots (b) a medicine reminder (c) a lost-and-found board (d) a bill splitter
9. 9.🧩 Which input is best for choosing a volume level? (a) a switch (b) a title (c) a slider (d) a text box
10. 10.🔢 After an app is released, which comes FIRST? (a) fix and improve (b) list what to fix (c) read user reviews (d) test it again
11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
12. 12.True or false: sorting the scores is an output. (a) False (b) True
13. 13.True or false: a website comes from an app store. (a) False (b) True
14. 14.🔢 In a quiz-app flow, which comes LAST? (a) tap “Start quiz” (b) read a question (c) pick an answer (d) see the final score
15. 15.🎯 Which app would help this user most: a grandparent with weak eyesight? (a) a pocket-money tracker (b) a recipe finder (c) a water reminder (d) a big-text reader
16. 16.🔘 Our rule: buttons are at least 48 px tall. The Save button is 20 px tall. How many px taller must it be?
17. 17.🔁 What number does this code show?
    let steps = [20, 18, 10, 17, 2];
    let total = 0;
    for (let i = 0; i < steps.length; i++) {
      total = total + steps[i];
    }
    show(total);
18. 18.🔍 Which is the odd one out? (a) write the store text (b) let friends try it (c) share the download link (d) put it on an app store
19. 19.🧭 What does the back button usually do? (a) deletes the page (b) goes to the last screen (c) opens settings (d) closes all apps
20. 20.🧰 In function tip(bill), what is bill? (a) a loop (b) a parameter (c) a screen (d) an event
21. 21.🔢 In a food-order flow, which comes LAST? (a) open the menu (b) add it to the cart (c) check the cart (d) track the order
22. 22.👆 The user taps the button 3 times. What does the label show now?
    let on = false;
    button.onTap = function () {
      on = !on;
      if (on) {
        label.text = "ON";
      } else {
        label.text = "OFF";
      }
    }; (a) OFF (b) ON
23. 23.🖼️ In this wireframe (top to bottom), which part is at the very bottom?
    [ tab bar ]
    [ Save button ]
    [ Add button ]
    [ big picture ]
    [ search box ] (a) Add button (b) Save button (c) search box (d) tab bar
24. 24.Which of these happens at the release stage? (a) write the code (b) let friends try it (c) share the download link (d) write down the bugs
25. 25.👆 The user taps the button 1 times. What does the label show now?
    let on = false;
    button.onTap = function () {
      on = !on;
      if (on) {
        label.text = "ON";
      } else {
        label.text = "OFF";
      }
    }; (a) OFF (b) ON
26. 26.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) greet() (d) run greet
27. 27.🔢 In a photo-post flow, which comes first: “take the photo” or “write a caption”? (a) take the photo (b) write a caption
28. 28.🧪 How many of these test cases pass?
    🚚 Rule: delivery is free (0) when the order is 400 or more; otherwise it costs 40.
    function delivery(total) {
      if (total >= 400) {
        return 0;
      }
      return 40;
    }
    Test 1: delivery(250) → expected 40
    Test 2: delivery(850) → expected 0
    Test 3: delivery(700) → expected 0
29. 29.🗒️ Version 1 of a homework planner must be ready in 9 days. How many days are left for extras after the must-haves?
    add a homework task: 1 days
    set a due date: 2 days
    see tasks by day: 2 days
30. 30.🧪 One test case fails. Which one?
    📝 Rule: a quiz is passed with 8 or more right answers.
    function result(right) {
      if (right > 8) {
        return "Pass";
      }
      return "Try again";
    }
    Test 1: result(10) → expected Pass
    Test 2: result(5) → expected Try again
    Test 3: result(8) → expected Pass (a) Test 2 (b) Test 1 (c) Test 3
31. 31.🔀 When does the else part run? (a) never (b) always (c) when the test is false (d) when the test is true
32. 32.📊 Survey: which problem bugs you most? How many students voted in all?
    forgetting homework: 5 votes
    forgetting birthdays: 7 votes
    wasting pocket money: 10 votes
33. 33.🧪 How many of these test cases pass?
    🚚 Rule: delivery is free (0) when the order is 800 or more; otherwise it costs 40.
    function delivery(total) {
      if (total > 800) {
        return 0;
      }
      return 40;
    }
    Test 1: delivery(1050) → expected 0
    Test 2: delivery(600) → expected 40
    Test 3: delivery(900) → expected 0
34. 34.🐞 This code has a bug. What number SHOULD it show, if every line did what its comment says?
    line 1: let points = 38; // start at 37
    line 2: points = points + 3; // add 3
    line 3: points = points + 4; // add 4
    line 4: show(points); // show it
35. 35.Which of these makes the app harder to use? (a) strong colour contrast (b) text that can grow (c) colour as the only clue (d) labels on every icon
36. 36.🔍 Which is the odd one out? (a) let friends try it (b) try every button (c) write down the bugs (d) share the download link
37. 37.Which of these requests is fair? (a) quiz app → microphone (b) calling app → contacts (c) torch → contacts (d) calculator → location
38. 38.🔀 What does this PIN rule show?
    let pin = "8277";
    if (pin.length === 4) {
      show("PIN saved");
    } else {
      show("Use 4 digits");
    } (a) Use 4 digits (b) PIN saved
39. 39.✏️ Is this true of a wireframe or of a final design: shows where things go? (a) a wireframe (b) a final design
40. 40.💾 What number does this code show?
    let friends = ["Aman", "Kabir"];
    friends.push("Zoya");
    friends.push("Meera");
    show(friends.length);

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