java8 Detailed Explanation and Example of Stack in Collection

java Collection Stack

Summary:

Stack is a stack, its characteristic is First In Last Out (FILO). Stack inherits from Vector (vector queue), since Vector is implemented by array, Stack also uses array rather than linked list.

The relationship between Stack and Collection is as follows:

based on Java8source code:

public class Stack<E> extends Vector<E> {
  public Stack() {//create an empty stack
  }
  public E push(E item) {//push
    addElement(item);
    return item;
  }
  //pop
  public synchronized E pop() {
    E obj;
    int len = size();
    obj = peek();
    removeElementAt(len - 1);
    return obj;
  }
  //return the top element of the stack without removing it
  public synchronized E peek() {
    int len = size();
    if (len == 0)
      throw new EmptyStackException();
    return elementAt(len - 1);
  }
  //determine if the stack is empty
  public boolean empty() {
    return size() == 0;
  }
  //find element and return stack depth
  public synchronized int search(Object o) {
    int i = lastIndexOf(o);
    if (i >= 0) {
      return size() - i;
    }
    return -1;
  }
  //serial version ID
  private static final long serialVersionUID = 1224463164541339165L;
}

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