ArrayList vs Stack

Both ArrayList and Stack are part of Java's java.util package, but they serve different purposes and have distinct characteristics:

ArrayList: A resizable array that allows dynamic storage of elements. It is used for general-purpose data storage and retrieval.
Stack: A subclass of Vector that follows the LIFO (Last In, First Out) principle, where elements are added and removed from the top of the stack.

Both ArrayList and Stack allow fast random access due to array-based storage.
ArrayList: Better for random access and manipulation of elements.
Stack: Optimized for stack operations like push and pop.

ArrayList: Not synchronized, so it's faster but requires external synchronization if used in multi-threaded environments.
Stack: Synchronized due to being a subclass of Vector. This makes it thread-safe but slower.

ArrayList: Provides typical List methods such as get(), add(), remove(), and indexOf().
Stack: Provides additional stack-specific methods:
- push(E item): Adds an element to the top of the stack.
- pop(): Removes and returns the element at the top.
- peek(): Returns the element at the top without removing it.
- empty(): Checks if the stack is empty.
- search(Object o): Returns the position of an object in the stack.

ArrayList

  ArrayList<String> list = new ArrayList<>();
  list.add("A");
  list.add("B");
  System.out.println(list.get(1));

Stack

  Stack<String> stack = new Stack<>();
  stack.push("A");
  stack.push("B");
  System.out.println(stack.pop());

ArrayList: When we need dynamic lists for storing and accessing data efficiently in general-purpose scenarios.
Stack: When LIFO operations are explicitly required, like in undo mechanisms, recursion tracking, or expression evaluation.

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