红宝石 |哈希 compare_by_identity()函数

Hash#compare_by_identity ()是一种 Hash 类方法，它将哈希键与其身份进行比较，并将完全相同的对象视为相同的键。

Syntax: Hash.compare_by_identity ()

Parameter: Hash array

Return: compares the hash key with its identity

示例 #1：

# Ruby code for compare_by_identity () method
  
# declaring Hash value
a = {a:100, b:nil}
  
# declaring Hash value
b = {a:100, c:nil, b:"b"}
  
# declaring Hash value
c = {a:100}
  
puts "compare_by_identity  a : #{a.compare_by_identity}\n\n"
  
puts "compare_by_identity  b : #{b.compare_by_identity}\n\n"
  
puts "compare_by_identity  b : #{c.compare_by_identity}\n\n"

输出 ：

compare_by_identity  a : {:a=>100, :b=>nil}

compare_by_identity  b : {:a=>100, :c=>nil, :b=>"b"}

compare_by_identity  b : {:a=>100}

示例 #2：

# Ruby code for compare_by_identity () method
  
# declaring Hash value
a = { "a" => 100, "b" => 200 }
  
# declaring Hash value
b = {"a" => 100}
  
# declaring Hash value
c = {"a" => 100, "c" => "c", "b" => 200}
  
puts "compare_by_identity  a : #{a.compare_by_identity}\n\n"
  
puts "compare_by_identity  b : #{b.compare_by_identity}\n\n"
  
puts "compare_by_identity  b : #{c.compare_by_identity}\n\n"

输出 ：

compare_by_identity  a : {"a"=>100, "b"=>200}

compare_by_identity  b : {"a"=>100}

compare_by_identity  b : {"a"=>100, "c"=>"c", "b"=>200}