ruby hash方法

Hash.invert方法 (Hash.invert Method)

In this article, we will study about Hash.invert Method. The working of this method can be predicted with the help of its name but it is not as simple as it seems. Well, we will understand this method with the help of its syntax and program code in the rest of the content.

在本文中，我們將研究Hash.invert方法 。 可以借助其名稱來預測此方法的工作，但是它并不像看起來那樣簡單。 好了，我們將在其余內容中借助其語法和程序代碼來理解此方法。

Method description:

方法說明：

This method is a public instance method that is defined in Ruby library especially for Hash class. This method works in a way that it creates a new hash object in which the keys of the self hash are values and values of the self hash are keys. If a key with the same values already exists in the hash object then the last key will be utilized and the previous one will be discarded. This method is one of the examples of non-destructive methods, where the changes created by the method are temporary.

此方法是在Ruby庫中定義的公共實例方法，特別是針對Hash類。 此方法的工作方式是創建一個新的哈希對象，其中自哈希的鍵是值，而自哈希的值是鍵。 如果散列對象中已經存在具有相同值的鍵，則將使用最后一個鍵，而前一個鍵將被丟棄。 此方法是非破壞性方法的示例之一，其中該方法創建的更改是臨時的。

Syntax:

句法：

    Hash_object.invert

Argument(s) required:

所需參數：

This method does not require any argument.

此方法不需要任何參數。

Example 1:

范例1：

=begin
Ruby program to demonstrate invert method
=end	
hash1={"color"=>"Black","object"=>"car","love"=>"friends","fruit"=>"Kiwi","vege"=>"potato"}
puts "Hash.invert implementation"
ary = hash1.invert
puts "Hash object after inverting: #{ary}"
puts "Self hash object : #{hash1}"

Output

輸出量

Hash.invert implementation
Hash object after inverting: {"Black"=>"color", "car"=>"object", "friends"=>"love", "Kiwi"=>"fruit", "potato"=>"vege"}
Self hash object : {"color"=>"Black", "object"=>"car", "love"=>"friends", "fruit"=>"Kiwi", "vege"=>"potato"}

Explanation:

說明：

In the above code, you can observe that we are inverting the hash object with the help of the Hash.invert method. In the new hash, the keys are values and values are keys. You can see that this method is not creating any impact upon the actual hash because this method is one of the examples of non-destructive methods.

在上面的代碼中，您可以觀察到我們在Hash.invert方法的幫助下反轉了哈希對象。 在新的哈希中，鍵是值，而值是鍵。 您可以看到該方法不會對實際哈希產生任何影響，因為該方法是非破壞性方法的示例之一。

Example 2:

范例2：

=begin
Ruby program to demonstrate invert method
=end	
hash1={"color"=>"Black","object"=>"car","love"=>"friends","fruit"=>"Kiwi","vege"=>"potato"}
puts "Hash.invert implementation"
ary = hash1.invert.invert
puts "Hash object after inverting: #{ary}"
puts "Self hash object : #{hash1}"

Output

輸出量

Hash.invert implementation
Hash object after inverting: {"color"=>"Black", "object"=>"car", "love"=>"friends", "fruit"=>"Kiwi", "vege"=>"potato"}
Self hash object : {"color"=>"Black", "object"=>"car", "love"=>"friends", "fruit"=>"Kiwi", "vege"=>"potato"}

Explanation:

說明：

In the above code, you can observe that we can invert a hash object with the help of the Hash.invert method. You can even see that we can do cascading of methods and we are getting the same hash after invoking invert twice.

在上面的代碼中，您可以觀察到我們可以借助Hash.invert方法反轉哈希對象。 您甚至可以看到我們可以級聯方法，并且調用兩次invert后得到相同的哈希值。

翻譯自: https://www.includehelp.com/ruby/hash-invert-method-with-example.aspx

ruby hash方法