When to use function declarations and expressions?
Function Declarations vs. Function Expressions in JavaScript
In JavaScript, defining functions can be achieved through either function declarations or function expressions, each serving different purposes and use cases within your code. MDN documents both the function declaration and the function expression.
Understanding Function Declarations
Function declarations are a familiar syntax in JavaScript, characterized by the function keyword, followed by a function name, parameters, and the function body enclosed in curly braces. A key feature of function declarations is hoisting, allowing these functions to be called before they are defined in the code. This is particularly useful for organizing code with helper functions or when a function needs to be used throughout various parts of a script.
The Flexibility of Function Expressions
Function expressions, on the other hand, involve assigning a function (anonymous or named) to a variable. Unlike function declarations, the function itself is not hoisted: only the variable is (as undefined with var, or uninitialized with let/const), so the expression must be evaluated before it can be invoked. This characteristic lends function expressions a degree of flexibility, making them suitable for use cases like passing functions as arguments, defining... premium content.
