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feat(curriculum): javascript comparisons quiz (#56633)
This commit is contained in:
Joe Steven
@@ -17,439 +17,506 @@ Answer all of the questions below correctly to pass the quiz.
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#### --text--
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Placeholder question
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What's the difference between `==` and `===`?
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#### --distractors--
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Placeholder distractor 1
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There is no difference, both have the exact same function.
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---
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Placeholder distractor 2
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`==` checks both values and its data type, while `===` only checks for value.
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---
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Placeholder distractor 3
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Both operators check the data type of the value, but only `===` compares values deeply.
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#### --answer--
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Placeholder answer
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`===` compares the value and type without type coercion, while `==` attempts to convert them to the same type before comparing.
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### --question--
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#### --text--
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Placeholder question
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```js
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console.log(5 === "5");
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```
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What's the output of the code above?
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#### --distractors--
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Placeholder distractor 1
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`true`
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---
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Placeholder distractor 2
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`NaN`
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---
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Placeholder distractor 3
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An error is raised.
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#### --answer--
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Placeholder answer
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`false`
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### --question--
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#### --text--
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Placeholder question
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Which of the following is NOT a comparison operator?
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#### --distractors--
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Placeholder distractor 1
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`===`
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---
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Placeholder distractor 2
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`!==`
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---
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Placeholder distractor 3
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`<=`
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#### --answer--
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Placeholder answer
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`?==`
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### --question--
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#### --text--
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Placeholder question
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Which logical operation does `||` represent?
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#### --distractors--
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Placeholder distractor 1
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XOR
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---
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Placeholder distractor 2
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AND
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---
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Placeholder distractor 3
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NOT
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#### --answer--
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Placeholder answer
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OR
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### --question--
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#### --text--
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Placeholder question
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```js
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console.log(5 === 2 + 3 || 4 == 2);
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```
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What's the output of the code above?
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#### --distractors--
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Placeholder distractor 1
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`undefined`
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---
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Placeholder distractor 2
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`false`
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---
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Placeholder distractor 3
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An error is raised.
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#### --answer--
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Placeholder answer
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`true`
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### --question--
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#### --text--
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Placeholder question
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What is a truthy and falsy value?
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#### --distractors--
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Placeholder distractor 1
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Value that's both `true` and `false`.
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---
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Placeholder distractor 2
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Value that changes depending on context.
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---
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Placeholder distractor 3
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Value that functions differently than `true` or `false` value.
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#### --answer--
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Placeholder answer
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A value that is considered `true` or `false` when encountered in a Boolean context.
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### --question--
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#### --text--
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Placeholder question
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```js
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if (1) {
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console.log("True!");
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}
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```
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What's printed to the console from the code above?
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#### --distractors--
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Placeholder distractor 1
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`false`
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---
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Placeholder distractor 2
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Nothing gets printed to the console.
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---
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Placeholder distractor 3
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An error is raised.
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#### --answer--
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Placeholder answer
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`"True!"`
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### --question--
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#### --text--
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Placeholder question
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Which of the following is NOT a truthy value?
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#### --distractors--
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Placeholder distractor 1
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`"false"`
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---
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Placeholder distractor 2
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`13`
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---
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Placeholder distractor 3
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`-1`
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#### --answer--
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Placeholder answer
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`0`
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### --question--
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#### --text--
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Placeholder question
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What's the difference between `undefined` and `null`?
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#### --distractors--
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Placeholder distractor 1
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No difference.
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---
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Placeholder distractor 2
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`null` is the implicit value assigned to variables.
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---
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Placeholder distractor 3
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`null` is a global property, `undefined` is not.
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#### --answer--
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Placeholder answer
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Variables not assigned a value has the value `undefined`, while `null` is used to represent the intentional absence of any object value.
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### --question--
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#### --text--
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Placeholder question
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```js
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const a = Boolean(undefined);
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```
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The value of `a` in the code above is...
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#### --distractors--
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Placeholder distractor 1
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`undefined`
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---
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Placeholder distractor 2
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`true`
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---
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Placeholder distractor 3
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`NaN`
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#### --answer--
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Placeholder answer
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`false`
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### --question--
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#### --text--
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Placeholder question
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```js
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if (2 == 2) {
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console.log("A");
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} else {
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console.log("B");
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}
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```
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What's printed to the console when the code above executes?
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#### --distractors--
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Placeholder distractor 1
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An error is raised.
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---
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Placeholder distractor 2
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`"B"`
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---
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Placeholder distractor 3
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Nothing gets printed to the console.
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#### --answer--
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Placeholder answer
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`"A"`
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### --question--
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#### --text--
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Placeholder question
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```js
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if (2 == "2") {
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// Statement
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}
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```
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What will happen when the code is ran?
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#### --distractors--
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Placeholder distractor 1
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The statement will output a warning and exits the program.
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---
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Placeholder distractor 2
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The statement will not run.
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---
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Placeholder distractor 3
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The statement will throw an error.
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#### --answer--
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Placeholder answer
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The statement will run.
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### --question--
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#### --text--
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Placeholder question
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```js
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if (2 == "2") {
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const a = 2;
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}
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console.log(a);
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```
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What is printed to the console with code above?
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#### --distractors--
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Placeholder distractor 1
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`2`
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---
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Placeholder distractor 2
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Nothing gets printed.
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---
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Placeholder distractor 3
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`undefined`
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#### --answer--
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Placeholder answer
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An error is raised.
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### --question--
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#### --text--
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Placeholder question
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What happens when you don't include `break` while implementing a switch statement?
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#### --distractors--
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Placeholder distractor 1
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The switch statement will stop abruptly.
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---
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Placeholder distractor 2
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The switch statement will throw an error after previous statement.
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---
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Placeholder distractor 3
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The switch statement will exit after the first match.
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#### --answer--
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Placeholder answer
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The code continues to evaluate the following case statements, even after finding a match.
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### --question--
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#### --text--
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Placeholder question
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```js
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const a = 2;
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if (1 == "1") {
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let b = 3;
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console.log(a + b);
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}
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console.log(b);
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```
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What will be printed to the console from the code above?
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#### --distractors--
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Placeholder distractor 1
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An error is raised.
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---
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Placeholder distractor 2
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```js
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5
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3
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```
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---
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Placeholder distractor 3
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```js
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5
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undefined
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```
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#### --answer--
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Placeholder answer
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`5`, and then an error is raised.
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### --question--
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#### --text--
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Placeholder question
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What keyword is used in a switch statement to handle cases when all of the specified cases are false?
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#### --distractors--
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Placeholder distractor 1
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`then`
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---
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Placeholder distractor 2
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`after`
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---
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Placeholder distractor 3
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`else`
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#### --answer--
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Placeholder answer
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`default`
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### --question--
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#### --text--
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Placeholder question
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What does the operator `&&` represent?
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#### --distractors--
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Placeholder distractor 1
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XOR
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---
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Placeholder distractor 2
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OR
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---
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Placeholder distractor 3
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NOT
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#### --answer--
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Placeholder answer
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AND
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### --question--
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#### --text--
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Placeholder question
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```js
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let x = 5;
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if (x > 1 && x < 10) {
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console.log("x is between 1 and 10");
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} else {
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console.log("x is not between 1 and 10");
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}
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```
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What is printed to the console with code above?
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#### --distractors--
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Placeholder distractor 1
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An error is raised.
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---
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Placeholder distractor 2
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Nothing is printed.
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---
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Placeholder distractor 3
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`"x is not between 1 and 10"`
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#### --answer--
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Placeholder answer
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`"x is between 1 and 10"`
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### --question--
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#### --text--
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Placeholder question
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What does the operator `!` do?
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#### --distractors--
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Placeholder distractor 1
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It will reverse the value of a variable.
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---
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Placeholder distractor 2
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It will do "AND" operation.
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---
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Placeholder distractor 3
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It will do "OR" operation.
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#### --answer--
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Placeholder answer
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It will negate the boolean value or converts a non-boolean expression to its opposite.
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### --question--
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#### --text--
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Placeholder question
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```js
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console.log(!!true);
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```
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What is printed to the console with the above code?
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#### --distractors--
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Placeholder distractor 1
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`false`
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---
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Placeholder distractor 2
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It raises an error, you can't double negate an expression.
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---
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Placeholder distractor 3
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`undefined`
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#### --answer--
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Placeholder answer
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`true`
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Reference in New Issue
Block a user