Student：Class的未定义方法'each'

I want to load a file, split its content into arrays, and have the class apply to the content.

我想加载一个文件,将其内容拆分为数组,并将该类应用于内容。

class Student
    def initialize( name, grade )
        @name = name
        @grade = grade
        @grade = @grade.to_i
        @newgrade = @grade*1.45
    end

    def show()
        return "#{@name} ,#{@grade} , #{@newgrade}" 
    end
end

# Opening the file into an array
arr = File.open("exam_results.txt", "r+")
allStudents = Array.new

for a in arr
    b = a.split(",")
    name = b[0]
    score = b[1]
    allStudents << Student.new(@name, @grade)
end

for i in Student
    puts show()
end

I'm getting

undefined method 'each' for Student:Class (NoMethodError)

Student的未定义方法'each':Class(NoMethodError)

on line 28, which is the puts show() line. Any clues on how I can get further on this?

在第28行,这是puts show()行。有关如何进一步了解这一点的任何线索?

2 个解决方案

#1

I think you have a typo there (among other things). You're doing this:

我认为你有一个错字(除其他外)。你这样做:

for i in Student
  puts show()
end

Clearly, the Student class is not a collection which you can iterate. I think, what you meant to write is this:

显然,Student类不是可以迭代的集合。我想,你打算写的是:

allStudents.each do |student|
  puts student.show
end

#2

That is because you are trying to iterate over "Student" class and not Array/Collection object at for i in Student

那是因为你试图在Student中迭代“Student”类而不是for i的Array / Collection对象

Basically you are doing it wrong. It rather should be something like

基本上你做错了。它应该是类似的东西

allStudents.each do |student|
  puts student.show
end

#1