红宝石 |哈希键？()函数

Hash#key?()是一个 Hash 类方法，用于检查与值对应的键是否存在。

Syntax: Hash.key?()

Parameter: Hash values

Return: true – if key corresponding to the value is present otherwise return false

示例 #1：

# Ruby code for Hash.key?() 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}
   
   
# key? Value
puts "Hash a key? form : #{a.key?("a")}\n\n"
   
puts "Hash b key? form : #{b.key?("c")}\n\n"
   
puts "Hash c key? form : #{c.key?("a")}\n\n"

输出 ：

Hash a key? form : true

Hash b key? form : false

Hash c key? form : false

示例 #2：

# Ruby code for Hash.key?() 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}
  
# key? Value
puts "Hash a key? form : #{a.key?("a")}\n\n"
  
puts "Hash b key? form : #{b.key?("c")}\n\n"
  
puts "Hash c key? form : #{c.key?("a")}\n\n"

输出 ：

Hash a key? form : true

Hash b key? form : false

Hash c key? form : true