Tag: JavaScript ES6

Understanding null vs undefined in JavaScript Step 1: What are null and undefined? In JavaScript, both null and undefined represent empty or missing values, but they are used in different….

Understanding NaN in JavaScript: Causes and How to Handle It Step 1: What is NaN? In JavaScript, NaN (Not-a-Number) is a special value that represents the result of an invalid….

Understanding Why 0 == “0” Evaluates to true in JavaScript Step 1: Understanding Loose Equality (==) in JavaScript In JavaScript, the loose equality operator (==) compares two values after converting….

Understanding Hoisting Leading to Unexpected Values in JavaScript Step 1: What is Hoisting? Hoisting is a JavaScript behavior where variable and function declarations are moved (“hoisted”) to the top of….

Understanding Global Variable Pollution in JavaScript Step 1: What is Global Variable Pollution? Global variable pollution occurs when too many variables are declared in the global scope, leading to: Example….

Understanding “this Context Lost in Callbacks” in JavaScript Step 1: Understanding this in JavaScript In JavaScript, this refers to the context in which a function is executed. The value of….

Understanding “Closure Capturing the Wrong Value in Loops” in JavaScript Step 1: What is a Closure? A closure in JavaScript is a function that remembers the variables from its parent….

Understanding Variable Scope Leakage in Loops (var in for Loops) in JavaScript In JavaScript, variable scope leakage in loops occurs when a variable declared inside a loop with var is….

Understanding “Uncaught TypeError: Cannot read property ‘x’ of undefined” in JavaScript The error “Uncaught TypeError: Cannot read property ‘x’ of undefined” occurs when JavaScript tries to access a property (x)….

Understanding “Uncaught SyntaxError: Identifier ‘[x]’ has already been declared” in JavaScript The error “Uncaught SyntaxError: Identifier ‘[x]’ has already been declared” occurs when JavaScript tries to declare a variable with….