Ziontech Solutions Interview Questions, Process, and Tips

The == operator checks for equality of value, while the === operator checks for equality of value and type.

• == is a loose equality comparison, while === is a strict equality comparison

• == performs type coercion, while === does not

• Example: 1 == '1' is true with ==, but false with ===

Strict mode is a feature in JavaScript that helps catch common coding errors and enforces more secure coding practices.

• Enables a stricter parsing and error handling mode in JavaScript

• Prevents the use of undeclared variables

• Disallows duplicate parameter names

• Throws errors for assignments to non-writable properties

• Helps to avoid accidentally creating global variables

• Introduced in ECMAScript 5

A callback function is a function that is passed as an argument to another function and is executed after a specific event occurs.

• Used in asynchronous programming to handle responses from events or API calls

• Allows for more flexible and modular code

• Commonly used in JavaScript for event handling, timers, and AJAX requests

Hoisting in JavaScript is a behavior where variable and function declarations are moved to the top of their containing scope during the compilation phase.

• Variable declarations are hoisted to the top of their scope, but not their assignments.

• Function declarations are fully hoisted, meaning they can be called before they are declared.

• Hoisting can lead to unexpected behavior if not understood properly.

Variable types are different data types that can be assigned to variables in programming languages.

• Variable types include integers, floating point numbers, strings, booleans, arrays, and objects.

• Examples: int age = 25; float price = 10.99; string name = 'John'; bool isTrue = true; array numbers = [1, 2, 3]; object person = {name: 'Alice', age: 30};