check distance to gameobject

C#
/// <summary>
/// Return distance between two points
/// </summary>
/// <param name="target"></param>
/// <param name="startPos"></param>
/// <returns></returns>
public float CheckDistanceTwoPoints(Vector3 target, Vector3 startPos)
{
	return Vector3.Distance(target, startPos);
}
Source

Also in C#: