java stack implementation

// construct with non-primative elements only!
Stack<String> stack = new Stack<String>();

// to add a value to the top of the stack:
stack.push("Hello");

// to return and remove a value from the top:
String top = stack.pop();

// to return a value without removing it:
String peek = stack.peek();

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

#include <stdio.h>

int MAXSIZE = 8;       
int stack[8];     
int top = -1;            

int isempty() {

   if(top == -1)
      return 1;
   else
      return 0;
}
   
int isfull() {

   if(top == MAXSIZE)
      return 1;
   else
      return 0;
}

int peek() {
   return stack[top];
}

int pop() {
   int data;
	
   if(!isempty()) {
      data = stack[top];
      top = top - 1;   
      return data;
   } else {
      printf("Could not retrieve data, Stack is empty.\n");
   }
}

int push(int data) {

   if(!isfull()) {
      top = top + 1;   
      stack[top] = data;
   } else {
      printf("Could not insert data, Stack is full.\n");
   }
}

int main() {
   // push items on to the stack 
   push(3);
   push(5);
   push(9);
   push(1);
   push(12);
   push(15);

   printf("Element at top of the stack: %d\n" ,peek());
   printf("Elements: \n");

   // print stack data 
   while(!isempty()) {
      int data = pop();
      printf("%d\n",data);
   }

   printf("Stack full: %s\n" , isfull()?"true":"false");
   printf("Stack empty: %s\n" , isempty()?"true":"false");
   
   return 0;
}

import java.util.Stack;
class Main {
    public static void main(String[] args) {
        Stack<String> animals= new Stack<>();
        // Add elements to Stack
        animals.push("Dog");
        animals.push("Horse");
        // Remove element from Stack
      	animals.pop();
      	// Access element from top of Stack
      	animals.peek();
    }
}

/* Java program to implement basic stack 
operations */
class Stack { 
    static final int MAX = 1000; 
    int top; 
    int a[] = new int[MAX]; // Maximum size of Stack 
  
    boolean isEmpty() 
    { 
        return (top < 0); 
    } 
    Stack() 
    { 
        top = -1; 
    } 
  
    boolean push(int x) 
    { 
        if (top >= (MAX - 1)) { 
            System.out.println("Stack Overflow"); 
            return false; 
        } 
        else { 
            a[++top] = x; 
            System.out.println(x + " pushed into stack"); 
            return true; 
        } 
    } 
  
    int pop() 
    { 
        if (top < 0) { 
            System.out.println("Stack Underflow"); 
            return 0; 
        } 
        else { 
            int x = a[top--]; 
            return x; 
        } 
    } 
  
    int peek() 
    { 
        if (top < 0) { 
            System.out.println("Stack Underflow"); 
            return 0; 
        } 
        else { 
            int x = a[top]; 
            return x; 
        } 
    } 
} 
  
// Driver code 
class Main { 
    public static void main(String args[]) 
    { 
        Stack s = new Stack(); 
        s.push(10); 
        s.push(20); 
        s.push(30); 
        System.out.println(s.pop() + " Popped from stack"); 
    } 
} 

// Java code to illustrate push() method 
import java.util.*; 
  
public class StackDemo { 
    public static void main(String args[]) 
    { 
        // Creating an empty Stack 
        Stack<Integer> STACK = new Stack<Integer>(); 
  
        // Use push() to add elements into the Stack 
        STACK.push(10); 
        STACK.push(15); 
        STACK.push(30); 
        STACK.push(20); 
        STACK.push(5); 
  
        // Displaying the Stack 
        System.out.println("Initial Stack: " + STACK); 
  
        // Pushing elements into the Stack 
        STACK.push(1254); 
        STACK.push(4521); 
  
        // Displaying the final Stack 
        System.out.println("Final Stack: " + STACK); 
    } 
} 

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;
}