SerializedProperty.DeleteArrayElementAtIndex

Description

Delete the element at the specified index in the array.

Additional resources: isArray, InsertArrayElementAtIndex, MoveArrayElement, DeleteCommand.

using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

public class DeleteArrayElementAtIndexExample : ScriptableObject
{
    public List<string> m_Data;

    [MenuItem("Example/SerializedProperty/DeleteArrayElementAtIndex Example")]
    static void MenuCallback()
    {
        DeleteArrayElementAtIndexExample obj = ScriptableObject.CreateInstance<DeleteArrayElementAtIndexExample>();
        obj.m_Data = new List<string>() { "The", "big", "cat", "jumped." };

        SerializedObject serializedObject = new SerializedObject(obj);
        SerializedProperty arrayProperty = serializedObject.FindProperty("m_Data");

        arrayProperty.DeleteArrayElementAtIndex(1);

        // With previous deletion index 2 now becomes the last element
        arrayProperty.DeleteArrayElementAtIndex(2);

        serializedObject.ApplyModifiedProperties();

        // Outputs "The cat"
        Debug.Log("Final array contents: " + string.Join(" ", obj.m_Data));
    }
}

using UnityEngine;
using UnityEditor;

public class DeleteArrayElementAtIndexExample2 : ScriptableObject
{
    public int[] m_Array = new int[] { 1, -1, -1, 3, -1, -1, 1, 3, -1 };

    [MenuItem("Example/SerializedProperty/DeleteArrayElementAtIndex Example 2")]
    static void MenuCallback()
    {
        var scriptableObject = ScriptableObject.CreateInstance<DeleteArrayElementAtIndexExample2>();

        using (var serializedObject = new SerializedObject(scriptableObject))
        {
            SerializedProperty arrayProperty = serializedObject.FindProperty("m_Array");

            // Iterate the array removing any negative numbers
            int arraySize = arrayProperty.arraySize;
            for (int index = 0; index < arraySize;)
            {
                var arrayElement = arrayProperty.GetArrayElementAtIndex(index);
                if (arrayElement.intValue < 0)
                {
                    arrayProperty.DeleteArrayElementAtIndex(index);
                    arraySize--;
                }
                else
                {
                    index++;
                }
            }

            serializedObject.ApplyModifiedProperties();
            Debug.Log("Cleaned array contents: " + string.Join(" ", scriptableObject.m_Array));
        }
    }
}