红宝石 |哈希 has_key?()函数

Hash#has_key?()是一个 Hash 类方法，用于检查给定键是否存在于哈希中。

Syntax: Hash.has_key?()

Parameter: Hash values

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

示例 #1：

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

输出 ：

Hash a has_key? form : false

Hash b has_key? form : false

Hash c has_key? form : false

示例 #2：

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

输出 ：

Hash a has_key? form : true

Hash b has_key? form : false

Hash c has_key? form : false