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ArrayElementAsRef<T>(void*, int)

Obtains a reference to a value of type T in an array at a specified index in memory.
Read time 1 minuteLast updated 13 days ago

Definition

public static ref T ArrayElementAsRef<T>(void* ptr, int index) where T : struct

Parameters

A pointer to the first element of the array. Ensure that this pointer is valid and points to allocated memory.

index

The zero-based index of the element to reference. Verify that the index is within the bounds of the array to prevent access violations.

Returns

Type

Description

TA reference to the value of type T at the specified index within the array. This reference allows direct manipulation of the value at its memory location.

Remarks

The
ArrayElementAsRef
method allows direct access to an array element by its index in memory. This method provides a reference to the element, enabling efficient data manipulation without copying. Use this method with care, as incorrect pointer usage can cause memory corruption or application crashes.
using UnityEngine;using Unity.Collections.LowLevel.Unsafe;using System.Runtime.InteropServices;public class ArrayElementAsRefExample : MonoBehaviour{ [StructLayout(LayoutKind.Sequential)] struct CustomStruct { public int Id; public float Value; } void Start() { int arrayLength = 5; // Allocate a buffer for CustomStruct using stackalloc unsafe { CustomStruct* structArray = stackalloc CustomStruct[arrayLength]; // Initialize the array with values for (int i = 0; i < arrayLength; i++) { structArray[i].Id = i; structArray[i].Value = i * 1.5f; } // Get a reference to an element using ArrayElementAsRef ref CustomStruct element = ref UnsafeUtility.ArrayElementAsRef<CustomStruct>(structArray, 2); element.Value = 99.9f; // Modify the value in place // Output the modified value Debug.Log($"Modified element at index 2: Id = {structArray[2].Id}, Value = {structArray[2].Value}"); } }}