What is Escape Analysis and how does it affect memory allocation?

Escape analysis is a compile-time process that determines whether a variable can safely reside on the stack or must 'escape' to the heap.

Stack allocation is fast, lock-free, and automatically cleaned up when a function returns. Heap allocation requires Garbage Collection (GC) overhead. If the compiler proves a variable's lifespan ends with the function, it allocates it on the stack. If a reference outlives the function (e.g., returning a pointer, storing in a global map, passing to an interface like fmt.Println), it escapes to the heap.