ruby hash方法

Hash.key？(obj)方法 (Hash.key?(obj) Method)

In this article, we will study about Hash.key?(obj) Method. The working of the method can't be assumed because of it's quite a different name. Let us read its definition and understand its implementation with the help of syntax and program codes.

在本文中，我們將研究Hash.key？(obj)方法 。 由于該方法的名稱完全不同，因此無法進行假設。 讓我們閱讀其定義并在語法和程序代碼的幫助下了解其實現。

Method description:

方法說明：

This method is a Public instance method and belongs to the Hash class which lives inside the library of Ruby language. Hash.key?() method is used to check whether a key(key-value) is a part of the particular Hash instance or not and that Hash instance should be a normal Hash instance. It will search through the whole Hash and gives you the result according to its search. Let us go through the syntax and demonstrating the program codes of this method.

此方法是Public實例方法，屬于Hash類，它位于Ruby語言庫中。 Hash.key？()方法用于檢查鍵(鍵值)是否為特定Hash實例的一部分，并且該Hash實例應為普通Hash實例。 它將搜索整個哈希，并根據其搜索結果。 讓我們來看一下語法，并演示該方法的程序代碼。

If you are thinking about what it will return then let me tell you, it will return a Boolean value. The returned value will be true if it finds the key inside the Hash and the return value will be false if it does not find the key to be the part of Hash instance.

如果您正在考慮它將返回什么，那么讓我告訴您， 它將返回一個布爾值 。 如果在哈希表中找到密鑰，則返回值將為true；如果找不到哈希表實例的一部分，則返回值為false。

Syntax:

句法：

    Hash_instance.key?(obj)

Argument(s) required:

所需參數：

This method only takes one parameter and that argument is nothing but the key whose presence we want to check.

此方法僅使用一個參數，而該參數不過是我們要檢查其存在性的鍵。

Example 1:

范例1：

=begin
Ruby program to demonstrate Hash.key? method
=end	
hsh = {"colors"  => "red","letters" => "a", "Fruit" => "Grapes"}
puts "Hash.key? implementation:"
puts "Enter the Key you want to search: "
ky = gets.chomp
if (hsh.key?(ky))
puts "Key found successfully"
else
puts "Key not found!"
end

Output

輸出量

Hash.key? implementation:
Enter the Key you want to search: 
colors
Key found successfully

Explanation:

說明：

In the above code, you can observe that we are invoking the Hash.key?() method on the normal Hash instance. It has returned true when it found the presence of key in the Hash object which is entered by the user.

在上面的代碼中，您可以觀察到我們在普通的Hash實例上調用Hash.key？()方法 。 當它在用戶輸入的哈希對象中發現密鑰存在時，它返回true。

Example 2:

范例2：

=begin
Ruby program to demonstrate Hash.key? method
=end	
hsh = {"colors"  => "red","letters" => "a", "Fruit" => "Grapes"}
hsh1 = {"cars"  => "800","bike" => "pulsar", "phone" => "A50"}
hsh2 = {"one"=> hsh, "two" => hsh1}
puts "Hash.key? implementation:"
puts "Enter the Key you want to search: "
ky = gets.chomp
if (hsh2.key?(ky))
puts "Key found successfully"
else
puts "Key not found!"
end

Output

輸出量

Hash.key? implementation:
Enter the Key you want to search: 
colors
Key not found!

Explanation:

說明：

In the above code, you can verify that Hash.key?() method does not work upon Hash instance which is the collection of multiple Hash instances. It will return false even if the object is a part of the Hash instance.

在上面的代碼中，您可以驗證Hash.key？()方法不適用于Hash實例，該實例是多??個Hash實例的集合。 即使對象是Hash實例的一部分，它也會返回false。

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

ruby hash方法