我正在学习ruby教程，我正在尝试通过最后一个测试可打印方法的例子。我通过直接在我的ruby程序中调用该方法测试了该方法，并且它确实吐出了所需的内容。什么阻止我的代码正确传递？非常感谢任何帮助。
这是rspec文件：
require 'dictionary'
describe Dictionary do
before do
@d = Dictionary.new
end
it 'is empty when created' do
@d.entries.should == {}
end
it 'can add whole entries with keyword and definition' do
@d.add('fish' => 'aquatic animal')
@d.entries.should == {'fish' => 'aquatic animal'}
@d.keywords.should == ['fish']
end
it 'add keywords (without definition)' do
@d.add('fish')
@d.entries.should == {'fish' => nil}
@d.keywords.should == ['fish']
end
it 'can check whether a given keyword exists' do
@d.include?('fish').should be_false
end
it "doesn't cheat when checking whether a given keyword exists" do
@d.include?('fish').should be_false # if the method is empty, this test passes with nil returned
@d.add('fish')
@d.include?('fish').should be_true # confirms that it actually checks
@d.include?('bird').should be_false # confirms not always returning true after add
end
it "doesn't include a prefix that wasn't added as a word in and of itself" do
@d.add('fish')
@d.include?('fi').should be_false
end
it "doesn't find a word in empty dictionary" do
@d.find('fi').should be_empty # {}
end
it 'finds nothing if the prefix matches nothing' do
@d.add('fiend')
@d.add('great')
@d.find('nothing').should be_empty
end
it "finds an entry" do
@d.add('fish' => 'aquatic animal')
@d.find('fish').should == {'fish' => 'aquatic animal'}
end
it 'finds multiple matches from a prefix and returns the entire entry (keyword + definition)' do
@d.add('fish' => 'aquatic animal')
@d.add('fiend' => 'wicked person')
@d.add('great' => 'remarkable')
@d.find('fi').should == {'fish' => 'aquatic animal', 'fiend' => 'wicked person'}
end
it 'lists keywords alphabetically' do
@d.add('zebra' => 'African land animal with stripes')
@d.add('fish' => 'aquatic animal')
@d.add('apple' => 'fruit')
@d.keywords.should == %w(apple fish zebra)
end
it 'can produce printable output like so: [keyword] "definition"' do
@d.add('zebra' => 'African land animal with stripes')
@d.add('fish' => 'aquatic animal')
@d.add('apple' => 'fruit')
@d.printable.should == %Q{[apple] "fruit"\n[fish] "aquatic animal"\n[zebra] "African land animal with stripes"}
end
end
这是我迄今为止为可打印功能创建的内容：
class Dictionary
def initialize(opts = {})
@opts = opts
end
def entries
@opts
end
def add(opts)
opts.is_a?(String) ? @opts.merge!(opts => nil) : @opts.merge!(opts)
end
def keywords
@opts.keys.sort
end
def include?(key)
@opts.has_key?(key)
end
def find(key)
@opts.select { |word,defin| word.scan(key).join == key }
end
def printable
opts_sorted = @opts.sort_by { |word,defin| word}
opts_sorted.each do |word,defin|
print "[#{word}] \"#{defin}\"\n"
end
end
end
这是错误：
1) Dictionary can produce printable output like so: [keyword] "definition"
Failure/Error: @d.printable.should == %Q{[apple] "fruit"\n[fish] "aquatic animal
"\n[zebra] "African land animal with stripes"}
expected: "[apple] \"fruit\"\n[fish] \"aquatic animal\"\n[zebra] \"African lan
d animal with stripes\""
got: [["apple", "fruit"], ["fish", "aquatic animal"], ["zebra", "African
land animal with stripes"]] (using ==)
Diff:
@@ -1,4 +1,4 @@
-[apple] "fruit"
-[fish] "aquatic animal"
-[zebra] "African land animal with stripes"
+["apple", "fruit"]
+["fish", "aquatic animal"]
+["zebra", "African land animal with stripes"]
# ./11_dictionary/dictionary_spec.rb:81:in `block (2 levels) in <top (required)>
'
答案 0 :(得分：1)
幸运的是，我刚刚完成了这件事！下面是答案代码，附有解释说明！我希望即使4年后这仍然有用！
class Dictionary # Create the class
attr_accessor :entries # Attribute Accessor; this is our setter and getter
def initialize(entries = {}) # Create constructor; if there is no value passed the default value is {}
@entries = {} # Declare instance variable with empty hash
if entries.is_a? Hash # is_a? is a method where it sees if its a class; Hash is the class we compare it to
entries.each {|key, value| @entries[key] = value} # if there is a value that's passed we copy the hash to our instance variable
end # End conditional
end # End constructor
def keywords # Main purpose of this method is to return what's inside our keys
keywords = [] # Create empty keyword variable
@entries.each_key {|key| keywords.push(key.to_s)} # each_key method only takes the keys in our hash and pushes them into the keywords array
keywords.sort # We sort the keywords variable
end # End method
def add(entry) # add method adds in an entry either a hash or a string
if entry.is_a? Hash # If the argument belongs to the class Hash; or if its a hash
entry.each {|key, value| @entries[key] = value} # Then we copy the key and values to our instance variable
elsif entry.is_a? String # If the arguemnt belongs to the class String; or if its a String
@entries[entry] = nil # We create a key for that string and set the value to nil
end # End conditional
end # End method
def include?(entry) # include? method this checks if the argument is in our entries and returns a boolean value
@entries.has_key?(entry) # has_key? checks the instance variable if it has the key
end # End method
def find(entry) # find method finds if certain letters are in our keys
@entries.select {|key| /#{entry}/.match(key)} # select gets the keys that match a certain keyword in our entries
# if @entries.has_key?(entry) # First attepmt to solve the test case
# @entries.select {|key,value| key == entry}
# else
# puts {}
# end
end # End method
def printable # printable method just prints out our entries like a dictionary
printable = [] # Create an empty array
@entries.sort.each do |key,value| # Sort and iterate to each key-value pair
printable.push("[#{key}] \"#{value}\"") # push the key-value pair formatted accordingly to the test case
end # End hash iteration
printable.join("\n") # join with newlines to get desired result
end # End method
end # End class
答案 1 :(得分：0)
我认为问题是你的printable方法没有返回你希望它返回的内容。
printable的返回值是方法的最后一个语句（opts_sorted.each ...）的值。您正在使用print输出预期的字符串，但这不会更改方法的返回值（这是您正在测试的）。
如果您想要返回正在打印的字符串，请尝试以下操作：
def printable
opts_sorted = @opts.sort_by { |word, defin| word}
opts_sorted.map{ |word, defin| "[#{word}] \"#{defin}\"\n" }.join
end
map会将哈希中的键值对转换为按照您希望的方式格式化的字符串数组，然后join会将它们附加到单个字符串中。