method in stack code example

Example 1: java stack methods

import java.util.Stack<E>;
Stack<Integer> myStack = new Stack<Integer>();
myStack.push(1);
myStack.pop();
myStack.peek();
myStack.empty(); // True if stack is empty

Example 2: stack implementation

typedef struct Nodo{
   Elem val;
   struct Nodo *next;
} *Stack;
Stack Empty(){return NULL;}
bool IsEmpty(Stack a){return a==NULL;}
Elem Top(Stack a){return a->val;} 
Stack Pop(Stack l){return l->next;}
Stack Push(Elem x,Stack res){
    Stack nuevo=(Stack)malloc(sizeof(struct Nodo));
    nuevo->val=x;
    nuevo->next=res;
    return nuevo;
}