In Swift, functions and closures are closely related concepts, but they have some key differences. Here is a detailed explanation:
Functions
Definition: Functions are named blocks of code that perform a specific task. They are declared using the func keyword.
Naming: Functions always have a name.
Scope: Functions can be defined globally or nested within other functions or types (e.g., classes, structs).
Invocation: Functions are typically invoked in the scope where they are defined.
Capture: Global functions do not capture values from their environment, while nested functions can capture values from their enclosing scope[3][5].
Closures
Definition: Closures are self-contained blocks of code that can capture and store references to variables and constants from their surrounding context. They are similar to anonymous functions, lambdas, or blocks in other programming languages.
Naming: Closures do not necessarily have a name. They are often used as inline, anonymous functions.
Scope: Closures can be defined inline within other functions or as standalone expressions. They cannot be defined globally in the same way functions can.
Invocation: Closures can be invoked at a different point in the code from where they are defined, making them useful for callbacks and asynchronous operations.
Capture: Closures capture values from their surrounding context, allowing them to "close over" those values and use them later[1][2][4][6].
