Simple Stack implementation using arrays in Java

CArrayStack.java

package io.nxz.interview.study.stack;

public class CArrayStack<T> {

  private int currentSize;
  private T[] items;

  public CArrayStack(int initialSize) {
    this.items = (T[]) new Object[initialSize];
  }

  public void push(T value) {
    if (currentSize == items.length) {
      grow();
    }
    items[currentSize++] = value;
  }

  public T pop() {
    if (currentSize < 1) {
      return null;
    }
    int removeIndex = currentSize - 1;
    T value = this.items[removeIndex];
    this.items[removeIndex] = null;
    currentSize--;
    return value;
  }

  public T peek() {
    if (currentSize < 1) {
      return null;
    }
    return this.items[currentSize - 1];
  }

  private void grow() {
    final T[] newArr = (T[]) new Object[currentSize + currentSize / 2];
    System.arraycopy(items, 0, newArr, 0, items.length);
    this.items = newArr;
  }

  public boolean isEmpty() {
    return currentSize < 1;
  }
}