The usage and function of square brackets [ ] in Unity

In Unity, square brackets [ ]are usually used to indicate properties, attributes (Attributes) or metadata (Metadata). These tags provide additional information and can be used to modify the behavior of classes, methods, fields, etc. or to set them in the editor.

Here are some common uses:

1. Attributes:

   • In C#, you can use attributes to attach metadata to classes, methods, fields, etc. In Unity, some features are used to modify the behavior of scripts, or to make custom settings in the editor.
   • Example: [SerializeField], [Header("My Header")], [Range(0, 100)].

2. Custom Inspector Controls (custom inspection panel control):

   • In the Unity editor, you can use attributes to customize how scripts are displayed in the inspector, such as creating buttons, text fields, and other controls.
   • Example: [Button("My Custom Button")], [TextArea].

3. Execution Order:

   • You can use [ExecuteInEditMode]the attribute to make the script run in edit mode, or use the [DefaultExecutionOrder]to set the execution order of the script.

4. Editor Scripts:

   • When customizing editor windows or tools, you can use [CustomEditor]and [CanEditMultipleObjects]to specify a custom editor for the script.

5. Validation:

   • Use [RequireComponent]attributes to specify that a class needs specific components attached to function properly, and the Unity Editor will verify this.

6. Menu Items:

   • Use [MenuItem]the attribute to create menu items for static methods that add custom functionality to the menu bar in the Unity editor.

Example:

using UnityEngine;

public class ExampleScript : MonoBehaviour
{
    
    
    [SerializeField]
    private int myInt;

    [Header("My Settings")]
    [Range(0, 10)]
    public float myFloat;

    [Button("My Custom Button")]
    private void CustomButtonFunction()
    {
    
    
        // Custom button behavior
    }

    [ExecuteInEditMode]
    private void UpdateEditMode()
    {
    
    
        // This method will execute in edit mode
    }
}

In summary, square brackets [ ]are used in Unity to mark properties, properties, and metadata in order to add more information in the script, or to customize the behavior and display of the script in the Unity editor.