JavaScript Statements Interview Questions

Here we have provided some frequently asked JavaScript (or JS) questions that will help you crack any JS interview. Here we will cover JS statements.

Q1. What kind of language is JavaScript?

Answer: JavaScript is an object-based language.

Q2. What are the uses of break and continue statements?

Answer: A break statement is used to exit from the loop that is currently processing. The continue statement is used to continue the next statement of the loop.

Q3. How can you break a string statement into multiple lines?

Answer: We can break a string statement into multiple lines using the backslash ‘\’ after the end of the first line. Any text written after the backslash will be printed on the next line.

Q4. Define for-in loop in JS.

Answer: We use the for-in loop to loop through the properties of the object. In every repetition of the loop, every property is associated with the variable name. The loop stops executing after all the properties of the object are used up.

Q5. Why do we use the return statement?

Answer: The return statement is used to return a value to where the function was invoked. We can also use it to end a function.

Q6. Define block statement in JS.

Answer: Block statement is used to combine multiple statements into a single statement to make things easier.

Q7. What type of statements are var and function and what are they used for?

Answer: var and function are called declaration statements. Var is used to declare local variables. The function is used to declare functions.

Q8. What do we use to end a JavaScript statement?

Answer: We use a semicolon ‘;’ to end JavaScript statements.

Q9. How do we use loops in JS?

Answer: We use loops when we need to execute a piece of code multiple times or as long as a specific condition is met. By using loops, we can complete a job in 3-4 lines which would have taken over 100 lines otherwise.

Q10. What are the different loops and mention what type of loop they are?

Answer: The types of loops are:

For loop (entry control)
For-in a loop (Entry control)
While loop (entry control)
Do while loop (exit control)

Q11. What is the purpose of the if statement?

Answer: Any statement present within the scope of the if statement gets executed only when a certain condition is met.

Q12. Which statement is used to create menu-driven programs?

Answer: The switch statement is used to create menu-driven programs. It executes conditions based on different cases.

Q13. What are JS statements?

Answer: JavaScript statements are commands which are used to tell the browser to perform a specific action.

Q14. When do we use “try and catch” statements?

Answer: Try statements are used to implement error handling. When an error occurs, the catch statements get executed.

Q15. What is [[[]]] used for?

Answer: The [[[]]] statement is used to declare three-dimensional arrays.

Q16. What type of errors cause unwanted infinite loops?

Answer: Logical errors cause unwanted infinite loops.

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