feat(curriculum): new questions for front end recursion quiz. (#57016)

Co-authored-by: Huyen Nguyen <25715018+huyenltnguyen@users.noreply.github.com>
2026-05-28 18:26:54 +00:00 · 2024-11-27 17:04:45 -05:00
parent 7d4f01263f
commit e29320f947
1 changed files with 276 additions and 100 deletions
@@ -17,439 +17,615 @@ To pass the quiz, you must correctly answer at least 17 of the 20 questions belo

 #### --text--

-Placeholder question
+What is recursion in programming?

 #### --distractors--

-Placeholder distractor 1
+A method of sorting arrays.

 ---

-Placeholder distractor 2
+A loop that never ends.

 ---

-Placeholder distractor 3
+A function that returns `undefined`.

 #### --answer--

-Placeholder answer
+A process in which a function calls itself.

 ### --question--

 #### --text--

-Placeholder question
+Which of the following is an example of recursion?

 #### --distractors--

-Placeholder distractor 1
+```javascript
+function factorial(n) {
+  let result = 1;
+
+  while (n > 0) {
+    result = result * n;
+    n--;
+  }
+
+  return result;
+}
+```

 ---

-Placeholder distractor 2
+```javascript
+function factorial(n) {
+  const arr = Array(n).fill().map((_, i) => i + 1);
+  return arr.reduce((acc, curr) => acc * curr, 1);
+}
+```

 ---

-Placeholder distractor 3
+```javascript
+function factorial(n) {
+  let result = 1;
+
+  for (let i = n; i > 0; i--) {
+    result *= i;
+  }
+
+  return result;
+}
+```

 #### --answer--

-Placeholder answer
+```javascript
+function factorial(n) {
+  if (n === 0 || n === 1) {
+    return 1;
+  }
+  return n * factorial(n - 1);
+}
+```

 ### --question--

 #### --text--

-Placeholder question
+What does the following function return?
+
+```javascript
+function sum(n) {
+  if (n === 0) return 0;
+  return n + sum(n - 1);
+}
+sum(3);
+```

 #### --distractors--

-Placeholder distractor 1
+3

 ---

-Placeholder distractor 2
+0

 ---

-Placeholder distractor 3
+A `Too much recursion` error.

 #### --answer--

-Placeholder answer
+6

 ### --question--

 #### --text--

-Placeholder question
+Given the following recursion:
+
+```javascript
+function sum(n) {
+  if (n === 0) return 0;
+  return n + sum(n - 1);
+}
+sum(3);
+```
+
+Which of the following is the order of the function calls in the call stack?

 #### --distractors--

-Placeholder distractor 1
+```js
+sum(0);
+sum(1);
+sum(2);
+sum(3);
+```

 ---

-Placeholder distractor 2
+```js
+sum(1);
+sum(2);
+sum(3);
+```

 ---

-Placeholder distractor 3
+```js
+sum(3);
+sum(2);
+sum(1);
+```

 #### --answer--

-Placeholder answer
+```js
+sum(3);
+sum(2);
+sum(1);
+sum(0);
+```

 ### --question--

 #### --text--

-Placeholder question
+What will this code print?
+
+```javascript
+function sayHello(n) {
+  if (n <= 0) return [];
+  return [`Hello ${n}`, ...sayHello(n - 1)];
+}
+console.log(sayHello(3));
+```

 #### --distractors--

-Placeholder distractor 1
+"Hello 3"

 ---

-Placeholder distractor 2
+An error

 ---

-Placeholder distractor 3
+`["Hello 3", "...Hello"]`

 #### --answer--

-Placeholder answer
+`["Hello 3", "Hello 2", "Hello 1"]`

 ### --question--

 #### --text--

-Placeholder question
+How many times will the function call itself?
+
+```javascript
+function mystery(n) {
+  if (n <= 1) return 1;
+  return mystery(n - 2);
+}
+mystery(5);
+```

 #### --distractors--

-Placeholder distractor 1
+2

 ---

-Placeholder distractor 2
+5

 ---

-Placeholder distractor 3
+4

 #### --answer--

-Placeholder answer
+3

 ### --question--

 #### --text--

-Placeholder question
+When should you use recursion?

 #### --distractors--

-Placeholder distractor 1
+All the time. Recursion is more superior than a traditional loop.

 ---

-Placeholder distractor 2
+In problems that require working with numbers.

 ---

-Placeholder distractor 3
+In problems that require working with strings.

 #### --answer--

-Placeholder answer
+In problems that involve performing repetitive tasks, or working with deeply nested arrays or objects, or tree-like structures.

 ### --question--

 #### --text--

-Placeholder question
+Which of the following is NOT true about recursion?

 #### --distractors--

-Placeholder distractor 1
+It must have a base case.

 ---

-Placeholder distractor 2
+It can replace loops.

 ---

-Placeholder distractor 3
+It can be memory-intensive.

 #### --answer--

-Placeholder answer
+It always returns 0.

 ### --question--

 #### --text--

-Placeholder question
+The following code handles a click event using recursion:
+
+```javascript
+element.onclick = function() {
+  this.onclick();
+}
+```
+
+What is the risk of using this approach?

 #### --distractors--

-Placeholder distractor 1
+Infinite event loop.

 ---

-Placeholder distractor 2
+Browser crash.

 ---

-Placeholder distractor 3
+Memory leak.

 #### --answer--

-Placeholder answer
+All of the above.

 ### --question--

 #### --text--

-Placeholder question
+What's wrong with this recursive DOM traversal?
+
+```javascript
+function findElement(element) {
+  if (element.id === 'target') return element;
+  findElement(element.firstChild);
+}
+```

 #### --distractors--

-Placeholder distractor 1
+Missing base case.

 ---

-Placeholder distractor 2
+Wrong parameter.

 ---

-Placeholder distractor 3
+Incorrect comparison.

 #### --answer--

-Placeholder answer
+Missing return for recursive call.

 ### --question--

 #### --text--

-Placeholder question
+The following recursion is missing a base case:
+
+```js
+function countDownToZero(number) {
+  // Base case goes here
+
+  console.log(number);
+  countDownToZero(number - 1);
+}
+```
+
+Which of the following options should be its base case?

 #### --distractors--

-Placeholder distractor 1
+```js
+if (number > 0) {
+  return;
+}
+```

 ---

-Placeholder distractor 2
+```js
+if (number !== 0) {
+  return;
+}
+```

 ---

-Placeholder distractor 3
+```js
+if (number === 0) {
+  return;
+}
+```

 #### --answer--

-Placeholder answer
+```js
+if (number < 0) {
+  return;
+}
+```

 ### --question--

 #### --text--

-Placeholder question
+Why must recursion have a base case?

 #### --distractors--

-Placeholder distractor 1
+To ensure the function always has a return value.

 ---

-Placeholder distractor 2
+To reduce the number of function calls.

 ---

-Placeholder distractor 3
+To ensure all recursive calls are executed in the correct order.

 #### --answer--

-Placeholder answer
+To provide a way for the function to break out of its recursive calls and prevent infinite loops.

 ### --question--

 #### --text--

-Placeholder question
+Which of the following is a potential drawback of using recursion?

 #### --distractors--

-Placeholder distractor 1
+The webpage takes longer to load.

 ---

-Placeholder distractor 2
+Recursion makes it impossible to debug the application.

 ---

-Placeholder distractor 3
+Recursion only works with large datasets.

 #### --answer--

-Placeholder answer
+Recursion is complicated and can make the code harder to understand.

 ### --question--

 #### --text--

-Placeholder question
+What will this recursive function do?
+
+```javascript
+function repeat(str) {
+  return str + repeat(str);
+}
+```

 #### --distractors--

-Placeholder distractor 1
+Return the string twice.

 ---

-Placeholder distractor 2
+Return `undefined`.

 ---

-Placeholder distractor 3
+Create an empty string.

 #### --answer--

-Placeholder answer
+Cause a stack overflow.

 ### --question--

 #### --text--

-Placeholder question
+What HTML structure is typically traversed recursively?

 #### --distractors--

-Placeholder distractor 1
+Style sheets

 ---

-Placeholder distractor 2
+Meta tags

 ---

-Placeholder distractor 3
+Script tags

 #### --answer--

-Placeholder answer
+The DOM tree

 ### --question--

 #### --text--

-Placeholder question
+What is a call stack?

 #### --distractors--

-Placeholder distractor 1
+A list of function calls that have been executed.

 ---

-Placeholder distractor 2
+A list of values that were returned by a function.

 ---

-Placeholder distractor 3
+A list of function declarations.

 #### --answer--

-Placeholder answer
+A data structure that keeps track of function calls and their execution order.

 ### --question--

 #### --text--

-Placeholder question
+What happens when a call stack exceeds its maximum size?

 #### --distractors--

-Placeholder distractor 1
+The webpage is automatically reloaded.

 ---

-Placeholder distractor 2
+All functions will be executed at once.

 ---

-Placeholder distractor 3
+The browser will immediately empty the stack.

 #### --answer--

-Placeholder answer
+A stack overflow error is thrown.

 ### --question--

 #### --text--

-Placeholder question
+What does this recursive function do?
+
+```javascript
+function changeString(str) {
+  if (str === "") return "";
+  return changeString(str.slice(1)) + str[0];
+}
+```

 #### --distractors--

-Placeholder distractor 1
+Duplicates a string.

 ---

-Placeholder distractor 2
+Removes vowels.

 ---

-Placeholder distractor 3
+Removes spaces.

 #### --answer--

-Placeholder answer
+Reverses a string.

 ### --question--

 #### --text--

-Placeholder question
+Which of the following is the correct execution order of a call stack?

 #### --distractors--

-Placeholder distractor 1
+All function calls are executed simultaneously.

 ---

-Placeholder distractor 2
+All function calls are executed in a random order.

 ---

-Placeholder distractor 3
+First in, first out.

 #### --answer--

-Placeholder answer
+Last in, first out.

 ### --question--

 #### --text--

-Placeholder question
+Given the following code:
+
+```javascript
+function foo() {
+  console.log("foo");
+  baz();
+}
+
+function bar() {
+  console.log("bar");
+  foo();
+}
+
+function baz() {
+  console.log("baz");
+}
+
+bar();
+```
+
+What will be printed in the console?

 #### --distractors--

-Placeholder distractor 1
+```javascript
+"bar"
+"baz"
+"foo"
+```

 ---

-Placeholder distractor 2
+```javascript
+"foo"
+"baz"
+"bar"
+```

 ---

-Placeholder distractor 3
+```javascript
+"baz"
+"foo"
+"bar"
+```

 #### --answer--

-Placeholder answer
+```javascript
+"bar"
+"foo"
+"baz"
+```