红宝石 |哈希长度（）方法

Hash#length() : length()是一种 Hash 类方法，它给出了散列中键值对的数量。

Syntax: Hash.length()

Parameter: Hash values

Return: number of key-value pairs in the hash

示例 #1：

# Ruby code for Hash.length() method
  
# declaring Hash value
a = {a:100, b:200}
  
# declaring Hash value
b = {a:100, c:300, b:200}
  
# declaring Hash value
c = {a:100}
  
  
# length Value
puts "Hash a length form : #{a.length}\n\n"
  
puts "Hash b length form : #{b.length}\n\n"
  
puts "Hash c length form : #{c.length}\n\n"

输出 ：

Hash a length form : 2

Hash b length form : 3

Hash c length form : 1

示例 #2：

# Ruby code for Hash.length() method
  
# declaring Hash value
a = { "a" => 100, "b" => 200 }
  
# declaring Hash value
b = {"a" => 100}
  
# declaring Hash value
c = {"a" => 100, "c" => 300, "b" => 200}
  
  
# length Value
puts "Hash a length form : #{a.length}\n\n"
  
puts "Hash b length form : #{b.length}\n\n"
  
puts "Hash c length form : #{c.length}\n\n"

输出 ：

Hash a length form : 2

Hash b length form : 1

Hash c length form : 3