当我运行一个简单的Ruby脚本时,将对象的字段转储到控制台的最简单方法是什么?

我正在寻找与PHP的print_r()类似的东西,它也将与数组一起工作。


可能是:

puts variable.inspect

您可能会发现method方法的用法,它为对象返回一个方法数组。它与print_r不同,但有时仍然有用。

>> "Hello".methods.sort
=> ["%", "*", "+", "<", "<<", "<=", "<=>", "==", "===", "=~", ">", ">=", "[]", "[]=", "__id__", "__send__", "all?", "any?", "between?", "capitalize", "capitalize!", "casecmp", "center", "chomp", "chomp!", "chop", "chop!", "class", "clone", "collect", "concat", "count", "crypt", "delete", "delete!", "detect", "display", "downcase", "downcase!", "dump", "dup", "each", "each_byte", "each_line", "each_with_index", "empty?", "entries", "eql?", "equal?", "extend", "find", "find_all", "freeze", "frozen?", "grep", "gsub", "gsub!", "hash", "hex", "id", "include?", "index", "inject", "insert", "inspect", "instance_eval", "instance_of?", "instance_variable_defined?", "instance_variable_get", "instance_variable_set", "instance_variables", "intern", "is_a?", "is_binary_data?", "is_complex_yaml?", "kind_of?", "length", "ljust", "lstrip", "lstrip!", "map", "match", "max", "member?", "method", "methods", "min", "next", "next!", "nil?", "object_id", "oct", "partition", "private_methods", "protected_methods", "public_methods", "reject", "replace", "respond_to?", "reverse", "reverse!", "rindex", "rjust", "rstrip", "rstrip!", "scan", "select", "send", "singleton_methods", "size", "slice", "slice!", "sort", "sort_by", "split", "squeeze", "squeeze!", "strip", "strip!", "sub", "sub!", "succ", "succ!", "sum", "swapcase", "swapcase!", "taguri", "taguri=", "taint", "tainted?", "to_a", "to_f", "to_i", "to_s", "to_str", "to_sym", "to_yaml", "to_yaml_properties", "to_yaml_style", "tr", "tr!", "tr_s", "tr_s!", "type", "unpack", "untaint", "upcase", "upcase!", "upto", "zip"]

p object

Ruby doc表示p。

p (* args) 对于每个对象,直接写入obj。检查之后 通过换行符转换到程序的标准输出。


to_yaml方法有时似乎很有用:

$foo = {:name => "Clem", :age => 43}

puts $foo.to_yaml

返回

--- 
:age: 43
:name: Clem

(这是否依赖于某些YAML模块被加载?或者这通常是可行的?)


把foo.to_json

可能会派上用场,因为json模块是默认加载的


如果你只是在对象中寻找实例变量,这可能是有用的:

obj.instance_variables.each do |var|
  puts [var, obj.instance_variable_get(var).inspect].join(":")
end

或者作为一行代码用于复制和粘贴:

obj.instance_variables.each{ |var| puts [var, obj.instance_variable_get(var).inspect].join(":")}

object.attribute_names

# => ["id", "name", "email", "created_at", "updated_at", "password_digest", "remember_token", "admin", "marketing_permissions", "terms_and_conditions", "disable", "black_list", "zero_cost", "password_reset_token", "password_reset_sent_at"]


object.attributes.values

# => [1, "tom", "tom@tom.com", Tue, 02 Jun 2015 00:16:03 UTC +00:00, Tue, 02 Jun 2015 00:22:35 UTC +00:00, "$2a$10$gUTr3lpHzXvCDhVvizo8Gu/MxiTrazOWmOQqJXMW8gFLvwDftF9Lm", "2dd1829c9fb3af2a36a970acda0efe5c1d471199", true, nil, nil, nil, nil, nil, nil, nil] 

如果你想打印一个已经缩进的JSON:

require 'json'
...
puts JSON.pretty_generate(JSON.parse(object.to_json))

我偶然发现了这条线索,因为我正在寻找类似的东西。我喜欢他们的回答,他们给了我一些想法,所以我测试了.to_hash方法,并在用例中工作得很好。秀:

object.to_hash


pp File.stat(“/ tmp”)

#<File::Stat
 dev=0x1000004,
 ino=71426291,
 mode=041777 (directory rwxrwxrwt),
 nlink=15,
 uid=0 (root),
 gid=0 (wheel),
 rdev=0x0 (0, 0),
 size=480,
 blksize=4096,
 blocks=0,
 atime=2021-04-20 17:50:33.062419819 +0800 (1618912233),
 mtime=2021-04-21 11:35:32.808546288 +0800 (1618976132),
 ctime=2021-04-21 11:35:32.808546288 +0800 (1618976132)>

我使用自己的解决方案打印和调试变量是https://github.com/igorkasyanchuk/wrapped_print

您可以简单地调用user。Wp在日志中查看该变量的值

而不是:

puts "-"*10
puts user.inspect
puts "-"*10