是否已注册

本课属于 Coddy GDScript 学习旅程的“逻辑与流程”单元。第 45 课，共 78 课。

挑战

简单

检查学生是否选修了某门课程。保留你在前面几步中写的所有内容。

1. 函数。在其他函数下方，编写 is_enrolled(student_name: String, course: String) -> bool：

如果 student_records 中没有这个姓名，就打印 Student '<name>' not found. 并返回 false。
否则，如果这门课程在该学生的 "courses" 集合中，就返回 true；如果不在，就返回 false。

2. 命令。在 ["show"] 上方，为 enrolled <name> <course> 添加一个分支，例如 enrolled Alice Math。它会打印 is_enrolled() 返回的值。对于以下命令：

add Alice 20 Math Physics
add Bob 22 Biology Chemistry
enrolled Alice Math
enrolled Alice Biology
enrolled Bob Biology
enrolled Charlie Math
exit

输出为：

Student 'Alice' added successfully.
Student 'Bob' added successfully.
true
false
true
Student 'Charlie' not found.
false
Goodbye!

如果找不到学生，会先显示提示信息，然后显示 false。

亲手试试

extends Node

# 每位学生：姓名 -> {"age": int, "grades": Array, "courses": 课程名称的集合}
var student_records := {}

func _ready():
	while true:
		var parts := Array(OS.read_string_from_stdin().split(" ", false))
		match parts:
			["add", var student, var age, ..]:
				add_student(student, int(age), parts.slice(3))
			["grade", var student, var grade]:
				add_grade(student, int(grade))
			["show"]:
				print(student_records)
			["exit"]:
				print("Goodbye!")
				break

func add_student(student_name: String, age: int, courses: Array) -> void:
	if student_records.has(student_name):
		print("Student '%s' already exists." % student_name)
		return
	var course_set := {}
	for course in courses:
		course_set[course] = true
	student_records[student_name] = {"age": age, "grades": [], "courses": course_set}
	print("Student '%s' added successfully." % student_name)

func add_grade(student_name: String, grade: int) -> void:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return
	student_records[student_name]["grades"].append(grade)
	print("Grade %d added for student '%s'." % [grade, student_name])