Hash.delete()方法以及Ruby中的示例
Hash.delete()方法
在本文中，我们将研究Hash.delete()方法。可以借助其名称来预测此方法的工作，但是它并不像看起来那样简单。好吧，我们将在其余内容中借助其语法和程序代码来理解此方法。
方法说明：
此方法是在ruby库中定义的公共实例方法，特别是针对Hash类。此方法的工作方式是删除调用时与该方法一起传递的键的键-值对。如果找不到该键，则返回'nil'。为了避免'nil'值，您可以将一个块与该方法一起传递，然后在找不到键的情况下返回该值的结果。
语法：
Hash_object.delete(object)
or
Hash_object.delete(object){block}Argument(s)需要：
您最多可以使用此方法传递一个对象。为了避免返回“nil”值，可以给出一个可选的块。
范例1：
=begin
Ruby program to demonstrate delete method
=end
hsh = Hash.new()hsh["color"] = "Black"
hsh["age"] = 20
hsh["school"] = "Angels' Academy Haridwar"
hsh["college"] = "Graphic Era University"
puts "Hash delete implementation"
puts "Enter the key you want to delete:"
ky = gets.chomp
if(hsh.delete(ky))
puts "Key deleted successfully"
else
puts "Key not found"
end
puts "Hash contents are : #{hsh}"输出结果
Hash delete implementation
Enter the key you want to delete:
school
Key deleted successfully
Hash contents are : {"color"=>"Black", "age"=>20, "college"=>"Graphic Era University"}说明：
在上面的代码中，您可以观察到该方法正在哈希对象上创建永久更改，并且键及其值已从哈希对象中删除。
范例2：
=begin
Ruby program to demonstrate delete method
=end
hsh = Hash.new()hsh["color"] = "Black"
hsh["age"] = 20
hsh["school"] = "Angels' Academy Haridwar"
hsh["college"] = "Graphic Era University"
puts "Hash delete implementation"
puts "Enter the key you want to delete:"
ky = gets.chomp
puts "#{hsh.delete(ky){|ky|"#{ky} not found"}}"
puts "Hash contents are : #{hsh}"输出结果
Hash delete implementation
Enter the key you want to delete:
car
car not found
Hash contents are : {"color"=>"Black", "age"=>20, "school"=>"Angels' Academy Haridwar", "college"=>"Graphic Era University"}说明：
在上面的代码中，您可以观察到，当在哈希对象中找不到该键时，该块已被执行，并且该块的处理值已返回。借助块可以做到这一点，否则必须从方法中返回'nil'值。delete()