A set of extension methods for declaring, getting, and checking for the existence of components in a single step.

TryGetComponentExtensions.cs

using UnityEngine;

public static class TryGetComponentExtensions
{
    #region GameObject Extensions

#if !UNITY_2019_1_OR_NEWER
    public static bool TryGetComponent<T>(this GameObject gameObject, out T component) where T : Component
    {
        component = gameObject.GetComponent<T>();
        return component;
    }
#endif

    public static bool TryGetComponentInChildren<T>(this GameObject gameObject, out T component) where T : Component
    {
        component = gameObject.GetComponentInChildren<T>();
        return component;
    }

    public static bool TryGetComponentInChildren<T>(this GameObject gameObject, bool includeInactive, out T component) where T : Component
    {
        component = gameObject.GetComponentInChildren<T>(includeInactive);
        return component;
    }

    public static bool TryGetComponentInParent<T>(this GameObject gameObject, out T component) where T : Component
    {
        component = gameObject.GetComponentInParent<T>();
        return component;
    }

    #endregion

    #region Component Extensions

#if !UNITY_2019_1_OR_NEWER
    public static bool TryGetComponent<T>(this Component source, out T component) where T : Component
    {
        component = source.GetComponent<T>();
        return component;
    }
#endif

    public static bool TryGetComponentInChildren<T>(this Component source, out T component) where T : Component
    {
        component = source.GetComponentInChildren<T>();
        return component;
    }

    public static bool TryGetComponentInChildren<T>(this Component source, bool includeInactive, out T component) where T : Component
    {
        component = source.GetComponentInChildren<T>(includeInactive);
        return component;
    }

    public static bool TryGetComponentInParent<T>(this Component source, out T component) where T : Component
    {
        component = source.GetComponentInParent<T>();
        return component;
    }

    #endregion

    #region Transform Extensions

#if !UNITY_2019_1_OR_NEWER
    public static bool TryGetComponent<T>(this Transform transform, out T component) where T : Component
    {
        component = transform.GetComponent<T>();
        return component;
    }
#endif

    public static bool TryGetComponentInChildren<T>(this Transform transform, out T component) where T : Component
    {
        component = transform.GetComponentInChildren<T>();
        return component;
    }

    public static bool TryGetComponentInChildren<T>(this Transform transform, bool includeInactive, out T component) where T : Component
    {
        component = transform.GetComponentInChildren<T>(includeInactive);
        return component;
    }

    public static bool TryGetComponentInParent<T>(this Transform transform, out T component) where T : Component
    {
        component = transform.GetComponentInParent<T>();
        return component;
    }

    #endregion
}