stack.java

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package stack;

 import java.util.Arrays;

/**
 *
 * @author DELL
 * @param <T>
 */
public class Stack<T> implements stackInterface<T> {
    
    private T[] array;

    //WHAT DOES THIS DO, WHAT ARE GENERICS
    
    public Stack() {
        this.array = new T[0];
    }

    /**
     * @param t
     */
    
    //we should use  an array

    @Override
    public void push(T t) {
        
        //creates a temp array with 1+ length from the first
        T[] temp = new T[array.length+1];

        //loops through array to add the old values
        System.arraycopy(array, 0, temp, 0, array.length);
        
        array = temp;
        
        array[array.length-1] = t;
    }

    @Override
    public T pop(T t) {
        
        //if the array is empty return null
        if(array.length == 0){
            return null;
        }
        //value to be popped
        T poppedValue;
        poppedValue = array[array.length-1];
        //make it smaller by one
        T[] temp = new T[array.length-1];
        //add from index 0 to 1 less
        System.arraycopy(array, 0, temp, 0, array.length-1);
        //return that first value
        return poppedValue;
    }

    @Override
    public T peek(T t) {
        //this is just to see what value is at the top of the stack
        
        //if the array is empty return null
        if(array.length == 0){
            return null;
        }
        
        return array[array.length-1];
        
    }

    @Override
    public boolean empty() {
        //checks if the array is empty
        return array.length == 0;
    
    }
}
    

stackInterface.java

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package stack;

/**
 *
 * @author DELL
 * @param <T>
 */
public interface stackInterface <T> {
    //adds object to top of the stack, doesnt return anything
    void push(T t);

    //removes object from top of the stack, returns the removed value
    T pop(T t);

    //checks what object is on top of stack
    T peek(T t);

    //checks if stack is empty, returns boolean
    boolean empty();
}

@Sisekelo Given your implementations, array.length is never equal to zero so all methods and checks that depend on that will always return false. Remember that at initializations, all the indices of the array is filled with null objects, hence array.length is always equal to the in this case 10.

@Sisekelo