Declaration vs Expression in JavaScript
In JavaScript, `declaration` and `expression` are fundamental concepts that serve different purposes. Declaration: A declaration is a statement that defines a variable, function, or class. It introduces a new identifier and specifies its type, scope, and initial value (if any). Declarations are typically used to define variables, functions, and classes. Examples of declarations: // Variable declaration let x; // Function declaration function add(a, b) { return a + b; } // Class declaration class Person { constructor(name, age) { this.name = name; this.age = age; } } Expression: An expression is a piece of code that evaluates to a value. It can be a simple value, a function call, an arithmetic operation, or a more complex expression. Expressions are typically used to perform calculations, assign values to variables, or pass arguments to functions. Examples of expressions: // Simple value expression 42; // Function call ex...