void EnforceUniqueIDs() { EnemyInfo currentEnemy = null; EnemyInfo previousEnemy = null; for (int i = 1; i < enemies.Count; i++) { currentEnemy = enemies[i]; previousEnemy = enemies[i - 1]; if (currentEnemy.Equals(previousEnemy)) { string messageFormat = "{0} and {1} have the same id. Please make sure "; messageFormat += "all enemies in the database have unique IDs."; throw new System.ApplicationException(string.Format(messageFormat, currentEnemy.name, previousEnemy.name)); } } }