Self-Realization of stack structure in Java

Package com.pinjia.shop.common.collection;/** * Created by Wangwei on 2017/1/3.        */public class mylinkedstack<t> {//define node data structure private class Node{public T data;        Public Node next;            Public node () {} public node (T data,node Next) {this.data = data;        This.next = next;    }}//stack top element Private Node top;    Number of elements private int size;        Insert element public void push (T element) {top = new Node (element,top);    size++;        }//out of stack operation public T pop () {Node oldNode = top;        top = top.next;        Release reference Oldnode.next = null;        size--;    Return oldnode.data;    }//returns the top element of the stack, but not the stack public T peek () {return top.data;    }//stack length public int length () {return size;    }//determine if the link stack is empty stack public boolean empty () {return size = = 0;        The public String toString () {///link stack is empty if (empty ()) return "[]"; Else{StringBuilder sb = new StriNgbuilder ("[");            For (Node current = top;current! = Null;current = Current.next) {sb.append (current.data.toString () + ",");            } int len = Sb.length ();        Return sb.delete (len-2,len). append ("]"). toString (); }} public static void main (string[] Args) {mylinkedstack<string> stack = new mylinkedstack<string&        Gt; ();        Constantly into the stack Stack.push ("aaaa");        Stack.push ("bbbb");        Stack.push ("cccc");        Stack.push ("dddd");        System.out.println (stack);        Access stack top element System.out.println ("access stack top element:" + stack.peek ());        pops up an element System.out.println ("first pop-up stack top element:" + stack.pop ());        Pop an element again System.out.println ("the second pop-up stack top element:" + stack.pop ());    System.out.println ("stack after two pops:" + stack); }}

　　

The following is an array-based implementation:

Package com.pinjia.shop.common.collection;/** * Created by Wangwei on 2017/1/3.    */public class myarraystack<t> {private object[] objs = new object[16];    private int size = 0;    public boolean isEmpty () {return size = = 0; public void Clear () {//to null the data in the array to facilitate GC reclamation for (int i = 0; i < size; i++) {objs[si        ze] = null;    } size = 0;    } public int length () {return size;        The public boolean push (T Data) {///determines whether an array expansion is required if (size >= Objs.length) {resize ();        } objs[size++] = data;    Return true;        }/** * Array expansion */private void resize () {object[] temp = new Object[objs.length * 3/2 + 1];            for (int i = 0; i < size; i++) {temp[i] = objs[i];        objs[i] = null;    } OBJS = temp;        Public T pop () {if (size = = 0) {return null;    } return (T) objs[--size]; } pUblic String toString () {StringBuilder sb = new StringBuilder ();        Sb.append ("myarraystack: [");            for (int i = 0; i < size; i++) {sb.append (objs[i].tostring ());            If (i! = Size-1) {sb.append (",");        }} Sb.append ("]");    return sb.tostring (); } public static void main (string[] Args) {myarraystack<integer> stack = new myarraystack<integer> ()        ;        Stack.push (12);        Stack.push (13);        System.out.println (stack.length ());    System.out.println (stack); }}

　　

Self-Realization of stack structure in Java