ValueLabs Senior Technical Lead Interview Questions and Answers

Closure in JavaScript is the combination of a function and the lexical environment within which that function was declared.

• Closure allows a function to access variables from its outer scope even after the outer function has finished executing.

• It is created every time a function is created, and it maintains a reference to the variables from its outer scope.

• Closure is commonly used in event handlers, callbacks, and maint

ConcurrentHashMap is a thread-safe version of HashMap in Java.

• ConcurrentHashMap allows multiple threads to read and write to the map concurrently without causing a ConcurrentModificationException.

• It achieves this by dividing the map into segments, each with its own lock, allowing multiple threads to access different segments simultaneously.

• ConcurrentHashMap is part of the java.util.concurrent package in Java.

• Example: C

Check if a string is a palindrome

• Iterate through the string from both ends and compare characters

• Ignore spaces and punctuation while checking for palindrome

• Convert string to lowercase for case-insensitive comparison