i want to take explain

src/main/java/core/basesyntax/ArrayList.java

@@ -1,48 +1,139 @@
 package core.basesyntax;
 
+import java.util.Arrays;
+import java.util.NoSuchElementException;
+
 public class ArrayList<T> implements List<T> {
+    private int count;
+    public static final int MAX_CAPACITY = 10;
+    private Object[] elements = new Object[MAX_CAPACITY];
     @Override
     public void add(T value) {
+        if (count >= elements.length) {
+            elements = grow();
+        }
+        elements[count] = value;
+        count++;
 
     }
 
     @Override
     public void add(T value, int index) {
+        checkIndexforAdd(index);
+        count++;
+        Object[] newArray = new Object[elements.length + 1];
+        if (count > MAX_CAPACITY) {
+             newArray = grow();
+
+        }
+        for (int i = 0; i < newArray.length; i++) {
+            if (i == index) {
+                break;
+            }
+            newArray[i] = elements[i];
+        }
+        newArray[index] = value;
+        for (int i = index + 1; i < newArray.length; i++) {
+            newArray[i] = elements[i - 1];
+        }
+        elements = newArray;
 
     }
 
     @Override
     public void addAll(List<T> list) {
+        if (count > elements.length) {
+            elements = grow();
+        }
+        for (int i = 0; i < elements.length; i++) {
+            elements[i] = list.get(i);
+        }
 
     }
 
     @Override
     public T get(int index) {
-        return null;
+        checkIndex(index);
+        return (T) elements[index];
     }
 
     @Override
     public void set(T value, int index) {
-
+        checkIndexforAdd(index);
+        elements[index] = value;
     }
 
     @Override
     public T remove(int index) {
-        return null;
+        checkIndex(index);
+        T element = (T) elements[index];
+        Object[] newArray1 = new Object[elements.length - 1];
+        for (int i = 0; i < newArray1.length; i++) {
+            if (i == index) {
+                break;
+            }
+            newArray1[i] = elements[i];
+        }
+        for (int i = index; i < newArray1.length; i++) {
+            newArray1[i] = elements[i + 1];
+        }
+        count--;
+        elements = newArray1;
+        return element;
     }
 
     @Override
     public T remove(T element) {
-        return null;
+        T result = null;
+        Object[] newArray1 = new Object[elements.length - 1];
+        int a = 0;
+        int thisExist = 0;
+        for (int i = 0; i < elements.length; i++) {
+            if (elements[i] == element || (element != null
+            && element.equals(elements[i]))) {
+                a = i;
+                result = element;
+                thisExist++;
+                break;
+            }
+            newArray1[i] = elements[i];
+        }
+        if (thisExist == 0) {
+            throw new NoSuchElementException();
+        }
+
+        for (int i = a; i < newArray1.length; i++) {
+            newArray1[i] = elements[i + 1];
+        }
+        count--;
+        elements = newArray1;
+        return result;
     }
 
     @Override
     public int size() {
-        return 0;
+        return count;
     }
 
     @Override
     public boolean isEmpty() {
-        return false;
+        return count == 0;
+    }
+
+    public Object[] grow() {
+        return Arrays.copyOf(elements, MAX_CAPACITY + (MAX_CAPACITY >> 1));
+    }
+
+    private void checkIndexforAdd(int index) {
+        if (index < 0 || index > count) {
+            throw new ArrayListIndexOutOfBoundsException("Incorrect index: " + index);
+        }
+
+    }
+
+    private void checkIndex(int index) {
+        if (index < 0 || index >= count) {
+            throw new ArrayListIndexOutOfBoundsException("Incorrect index: " + index);
+        }
     }
 }