Ruby Hash key?()函数

Hash#key?()是一个Hash类方法，用于检查值所对应的键是否存在。

语法。Hash.key?()

参数：哈希值

返回：true – 如果键对应的值是存在的，否则返回false

例子 #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

例子 #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