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What are template literals?

Template literals are a feature in JavaScript, introduced with ES6, that allow you to create strings that are more flexible and powerful than traditional string concatenation. They are enclosed by backticks (`) instead of single (') or double (") quotes.


Key Features of Template Literals:


1. String Interpolation:
○ Allows embedding expressions directly within the string using the ${expression} syntax.

○ Example:


const name = 'John';
const age = 30;
const greeting = Hello, my name is ${name} and I am ${age} years old.;
console.log(greeting);

// Output: Hello, my name is John and I am 30 years old.




1. Multiline Strings:
○ Template literals can span multiple lines without needing escape characters (\n).
○ Example:


const multiline = `This is a string
that spans across
multiple lines.`;
console.log(multiline);


Output--





1. Expression Evaluation:
○ Any valid JavaScript expression can be included inside the ${} placeholder.
○ Example:


const a = 5;
const b = 10;
console.log(`The sum of ${a} and ${b} is ${a + b}.`);
// Output: The sum of 5 and 10 is 15.



2. Tagged Templates:
○ A way to process template literals with a function.
○ Example:


function tag(strings, ...values) {
return strings[0] + values.map((val) => val.toUpperCase()).join("");
}
const result = tag`Hello ${"world"}!`;
console.log(result);
// Output: Hello WORLD!



3. Dynamic HTML or Other Markup:
○ Useful for dynamically constructing HTML or other content.
○ Example:
const title = 'Welcome';
const content = <h1>${title}</h1>;
console.log(content);
Syntax:

string text
string text ${expression} string text


Template literals are especially useful for creating complex strings and enhancing code readability.

Here are 20 JavaScript multiple-choice interview questions along with answers:

---

### 1. What is the output of the following code?

javascript 
console.log(typeof null); 

- A. "null"
- B. "object"
- C. "undefined"
- D. "number"

Answer: B. "object"

---

### 2. Which of the following is not a primitive data type in JavaScript?
- A. Number
- B. Object
- C. String
- D. Boolean

Answer: B. Object

---

### 3. What is the correct syntax to create an array in JavaScript?
- A. var arr = {};
- B. var arr = [];
- C. var arr = new Array();
- D. Both B and C

Answer: D. Both B and C

---

### 4. Which of the following methods is used to add an element to the end of an array?
- A. push()
- B. pop()
- C. shift()
- D. unshift()

Answer: A. push()

---

### 5. What is the output of the following code?

javascript 
console.log(2 + "2"); 

- A. 22
- B. 4
- C. NaN
- D. Error

Answer: A. 22

---

### 6. How do you write an arrow function in JavaScript?
- A. function => () {}
- B. () => {}
- C. => function {}
- D. () -> {}

Answer: B. () => {}

---

### 7. What will `console.log([] == false)` output?
- A. true
- B. false
- C. undefined
- D. Error

Answer: A. true

---

### 8. Which keyword is used to declare a constant variable in JavaScript?
- A. let
- B. var
- C. constant
- D. const

Answer: D. const

---

### 9. What is the purpose of `isNaN()` in JavaScript?
- A. Check if a value is a number
- B. Check if a value is not a number
- C. Check if a value is undefined
- D. Check if a value is null

Answer: B. Check if a value is not a number

---

### 10. What does `==` compare in JavaScript?
- A. Value only
- B. Type only
- C. Value and type
- D. None of the above

Answer: A. Value only

---

### 11. Which of the following is used to stop event propagation?
- A. stopPropagation()
- B. preventDefault()
- C. return false;
- D. clearPropagation()

Answer: A. stopPropagation()

---

### 12. What is the purpose of `JSON.stringify()`?
- A. Convert a JSON string to an object
- B. Convert an object to a JSON string
- C. Parse a URL string
- D. None of the above

Answer: B. Convert an object to a JSON string

---

### 13. Which method is used to combine two or more arrays in JavaScript?
- A. concat()
- B. merge()
- C. join()
- D. add()

Answer: A. concat()

---

### 14. What is the output of the following code?

javascript 
console.log("5" - 2); 

- A. 3
- B. 52
- C. "5-2"
- D. Error

Answer: A. 3

---

### 15. Which of the following is a falsy value in JavaScript?
- A. 0
- B. ""
- C. null
- D. All of the above

Answer: D. All of the above

---

### 16. What is a closure in JavaScript?
- A. A function inside an object
- B. A function bundled with its lexical environment
- C. A block of code inside curly braces
- D. None of the above

Answer: B. A function bundled with its lexical environment

---

### 17. How can you check if a variable is an array?
- A. typeof variable === "array"
- B. Array.isArray(variable)
- C. variable instanceof Array
- D. Both B and C

Answer: D. Both B and C

---

### 18. What is the purpose of `setTimeout()`?
- A. Repeats execution of code at specified intervals
- B. Executes a function after a delay
- C. Stops the execution of code
- D. None of the above

Answer: B. Executes a function after a delay

---

### 19. What will `console.log(!!"")` output?
- A. true
- B. false
- C. undefined
- D. Error

Answer: B. false

---

### **20. Which JavaScript feature