平均成绩
本课属于 Coddy GDScript 学习旅程的“逻辑与流程”单元。第 46 课，共 78 课。
挑战
简单计算一名学生的平均成绩。保留你在前面步骤中编写的所有内容。
1. 函数。在其他函数下方，编写 calculate_average_grade(student_name: String) -> float：
- 如果
student_records中没有这个名字，就打印Student '<name>' not found.并返回-1.0。实际的平均成绩不会是负数，因此调用方可以判断该学生不存在。 - 如果该学生还没有成绩，则返回
0.0。 - 否则，将成绩总和除以成绩数量，并以
float类型返回。
2. 命令。在 ["show"] 上方添加 average <name> 对应的分支。如果找到该学生，就打印保留两位小数的平均成绩：
["average", var student]:
var average := calculate_average_grade(student)
if average >= 0:
print("Average grade of '%s': %.2f" % [student, average])对于以下命令：
add Alice 20 Math Physics
add Bob 22 Biology Chemistry
grade Alice 90
grade Alice 85
grade Bob 75
average Alice
average Bob
average Charlie
exit输出为：
Student 'Alice' added successfully.
Student 'Bob' added successfully.
Grade 90 added for student 'Alice'.
Grade 85 added for student 'Alice'.
Grade 75 added for student 'Bob'.
Average grade of 'Alice': 87.50
Average grade of 'Bob': 75.00
Student 'Charlie' not found.
Goodbye!亲手试试
extends Node
# 每位学生：name -> {"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))
["enrolled", var student, var course]:
print(is_enrolled(student, course))
["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])
func is_enrolled(student_name: String, course: String) -> bool:
if not student_records.has(student_name):
print("Student '%s' not found." % student_name)
return false
return student_records[student_name]["courses"].has(course)
逻辑与流程中的所有课
自己练习： GDScript 在线编译器