1. What is an arrow function in JavaScript?
Answer:
Explanation:
Arrow functions provide a shorter syntax for writing function expressions in JavaScript. They allow for a more concise way to write functions.
2. How is an arrow function expressed in JavaScript?
Answer:
Explanation:
Arrow functions are defined using the arrow (=>) syntax, with parameters on the left side of the arrow and function statements on the right.
3. What is the main difference between arrow functions and traditional functions in terms of 'this'?
Answer:
Explanation:
Arrow functions do not have their own 'this' context; instead, 'this' refers to the surrounding lexical context.
4. Can arrow functions be used as constructors?
Answer:
Explanation:
Arrow functions cannot be used as constructors and will throw an error if used with the new keyword.
5. How does an arrow function return a single expression?
Answer:
Explanation:
In an arrow function, if you have a single expression, it is returned automatically without the need for the return keyword.
6. What happens when you use parentheses around the body of an arrow function?
Answer:
Explanation:
Using parentheses around the body of an arrow function indicates an implicit return. This is commonly used for returning object literals.
7. Can arrow functions be named?
Answer:
Explanation:
Arrow functions are anonymous. However, they can be named indirectly by assigning them to variables.
8. How do you handle multiple parameters in an arrow function?
Answer:
Explanation:
Multiple parameters in an arrow function are handled by separating them with a comma within parentheses.
9. What is a common use case for arrow functions in JavaScript?
Answer:
Explanation:
Arrow functions are commonly used for short callback functions due to their concise syntax.
10. How are arguments handled in an arrow function?
Answer:
Explanation:
Arrow functions do not have their own arguments object. However, you can handle arguments using rest parameters.
11. How does the arrow function treat the 'new.target' keyword?
Answer:
Explanation:
Arrow functions do not have a new.target keyword; using it within an arrow function will throw an error.
12. Can arrow functions be used as methods in an object literal?
Answer:
Explanation:
While you can use arrow functions as methods in object literals, it is not recommended because they inherit the 'this' value from the enclosing scope, which can lead to unexpected behavior.
13. What is the output of using 'this' inside an arrow function within a method?
Answer:
Explanation:
When using 'this' inside an arrow function that is within a method, 'this' refers to the global object, as arrow functions do not have their own 'this'.
14. Can you create immediately invoked function expressions (IIFE) with arrow functions?
Answer:
Explanation:
Arrow functions can be used to create immediately invoked function expressions (IIFE) by enclosing the arrow function and its invocation in parentheses.
15. How do you specify a default parameter value in an arrow function?
Answer:
Explanation:
Default parameter values in arrow functions are specified by assigning a value to the parameter in the function's parameter list.