class User:
    def __init__(self, name, employee_title):
        self.name = name
        self.employee_title = employee_title
        self.top_skills = []
        self.tasks_completed = {}
        self.task_types = {}
        self.task_efficiency = {}

    def add_skill(self, skill):
        self.top_skills.append(skill)

    def add_completed_task(self, task_name, task_type, efficiency):
        self.tasks_completed[task_name] = efficiency
        self.task_types[task_name] = task_type
        self.task_efficiency[task_name] = efficiency

    def get_task_efficiency(self, task_name):
        return self.task_efficiency.get(task_name, None)


# Example usage:
user = User("John Doe", "Software Developer")
user.add_skill("Python")
user.add_skill("JavaScript")
user.add_completed_task("Project A", "Development", 0.8)
user.add_completed_task("Project B", "Testing", 0.9)

print(user.name)  # Output: John Doe
print(user.employee_title)  # Output: Software Developer
print(user.top_skills)  # Output: ['Python', 'JavaScript']
print(user.tasks_completed)  # Output: {'Project A': 0.8, 'Project B': 0.9}
print(user.task_types)  # Output: {'Project A': 'Development', 'Project B': 'Testing'}
print(user.get_task_efficiency("Project A"))  # Output: 0.8
print(user.get_task_efficiency("Project C"))  # Output: None