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

allows functions to operate on objects irrespective of their type?**
- A. Closures
- B. Prototypes
- C. Polymorphism
- D. Hoisting

Answer: C. Polymorphism

---

1. What is the output of the following code?

   console.log(typeof null);
   

- A) "object"
- B) "null"
- C) "undefined"
- D) "boolean"

Answer: A) "object"

2. Which of the following is not a JavaScript data type?
- A) String
- B) Number
- C) Boolean
- D) Float

Answer: D) Float

3. What will the following code output?

   console.log(0 == '0');
   console.log(0 === '0');
   

- A) true, true
- B) true, false
- C) false, true
- D) false, false

Answer: B) true, false

4. **What is the purpose of the let keyword in JavaScript?**
- A) To declare a block-scoped variable
- B) To declare a global variable
- C) To declare a constant
- D) To declare a function
Answer: A) To declare a block-scoped variablele**
What will the following code output?t?**

   console.log(1 + "2" + "2");
   

- A) "122"
- B) "32"
- C) "14"
- D) "5"
Answer: A) "122"2"**
Which method is used to add an element to the end of an array?y?**
- A) push()
- B) pop()
- C) shift()
- D) unshift()

**Answer: A) push()**

7. **What is the output of the following code?**

   console.log(typeof NaN);
   

- A) "number"
- B) "NaN"
- C) "undefined"
- D) "Answer: A) "number") "number"**

8. **What does the this keyword refer to in a JavaScript method?**
- A) The function itself
- B) The global object
- C) The object that the method belongs to
- D) The paAnswer: C) The object that the method belongs tohod bWhat will the following code output?g code output?**

   console.log([] + []);
   

- A) "undefined"
- B) "null"
- C) ""
Answer: C) ""*AnsweWhich of the following is not a valid way to create a JavaScript object?Script object?**
- A) let obj = {};
- B) let obj = new Object();
- C) let obj = Object.create(null);
- D) let obj = new Object(null);

**Answer: D) let obj = new Object(null);**

11. **What is the output of the following code?**

    console.log(1 == true);
    console.log(0 == false);
    

- A) true, true
- B) true, false
- C) false, true
Answer: A) true, true*Answer: A) true, true**

12. **What is the purpose of the bind() method in JavaScript?**
- A) To bind a function to an object
- B) To bind an event to a function
- C) To bind a variable to a function
- D) To bind a Answer: A) To bind a function to an objectnd a fWhat will the following code output?the following code output?**

    console.log(typeof undefined);
    

- A) "undefined"
- B) "null"
- C) "objeAnswer: A) "undefined" **AnWhich of the following is not a JavaScript framework or library?ript framework or library?**
- A) React
- B) Angular
- Answer: D) Djangoo

What is the output of the following code?put of the following code?**

    console.log(2 + "2" - 1);
    

- A) "21"
- B) "22"
Answer: C) 21 D) 3

**Answer: C) 21**

16. **What is the purpose of the map() method in JavaScript?**
- A) To create a new array by applying a function to each element of an existing array
- B) To filter elements of an array based on a condition
- C) To reduce an array to a single value
- D) To sorAnswer: A) To create a new array by applying a function to each element of an existing arrayh elemWhat will the following code output?ill the following code output?**

    console.log(typeof []);
    

- A) "array"
- B) "object"
- C) "Answer: B) "object"ll"

Which of the following is not a valid JavaScript loop?s not a valid JavaScript loop?**
- A) for
- B) while
- C) do...while
- D) foreach

**Answer: D) foreach**

19. What is the output of the following code?

    console.log(1 === true);
    

- A) true
- B) false
- C) undefined
- D) null

Answer: B) false

20. **What is the purpose of the Promise object in JavaScript?**
- A) To handle asynchronous operations
- B) To handle synchronous operations
- C) To handle event listeners
- D) To handle DOM manipulation

Answer: A) To handle asynchronous operationsns**

These questions cover a range of JavaScript topics, including data types, operators, methods, and more, which are commonly asked in interviews.

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