Require vs Load

原文地址 : http://www.fromjavatoruby.com/2008/10/require-vs-load.html

关于两者的区别,原文讲的很清楚,这里只做简单翻译和实验,记录一下省得忘记 。

 

Require官方文档Kernel#require ,Load官方文档Kernel#load 。

区别有2点:

1.Load需要显示指出扩展名(LoadError)而require不用,require会自动加上.rb,.so,.o,.dll完成加载。
2.Load可以重复加载多次而require不行(第二次加载返回false)。

 

实验 :test.rb和 run.rb在同一目录。

test.rb

puts "This file is so useful I just want to use it everywhere!"

 run.rb

def reqFile(file)
  require file
end

def loadFile(file)
  load file
end

puts "\n"
puts 'reqFile Method1 ...'
puts reqFile('test')
puts 'reqFile Method1 ...'

puts "\n"
puts 'reqFile Method2 ...'
puts reqFile('test')
puts 'reqFile Method2 ...'

puts "\n"
puts 'loadFile Method1 ...'
puts loadFile('test.rb')
puts 'loadFile Method1 ...'

puts "\n"
puts 'loadFile Method2 ...'
puts loadFile('test.rb')
puts 'loadFile Method2 ...'

puts "\n"
puts 'loadFile Method3 ...'
puts loadFile('test')
puts 'loadFile Method3 ...'

 输出:

>ruby run.rb
run.rb:6:in `load': no such file to load -- test (LoadError)
	from run.rb:6:in `loadFile'
	from run.rb:31

reqFile Method1 ...
This file is so useful I just want to use it everywhere!
true
reqFile Method1 ...

reqFile Method2 ...
false
reqFile Method2 ...

loadFile Method1 ...
This file is so useful I just want to use it everywhere!
true
loadFile Method1 ...

loadFile Method2 ...
This file is so useful I just want to use it everywhere!
true
loadFile Method2 ...

loadFile Method3 ...
>Exit code: 1