Ruby 学习笔记 --块blocks
{} 单行的用；do...end 用
block可以带参数，也可以不带参数，参数使用||，
举例说明：
[Crabby@Crabby-Lee Book]$ irb
1.9.3-p125 :001 > sum = 0
=> 0
1.9.3-p125 :002 > (1..5).each do |v|
1.9.3-p125 :003 > name = 'smile'
1.9.3-p125 :004?> sum +=v
1.9.3-p125 :005?> end
=> 1..5
上例中name是块内的变量，离开块便不可以访问；块内可以访问块外的变量
1.9.3-p125 :016 > name = 'oooo'
1.9.3-p125 :017 > sum = 0
1.9.3-p125 :018 > (1..5).each do |v|
1.9.3-p125 :019 > name = 'inside' //如果没有显示定义块内的局部变量;name,则name将修改全局变量
1.9.3-p125 :020?> sum +=v
1.9.3-p125 :021?> end
1.9.3-p125 :022 > p sum
1.9.3-p125 :023 > p name //name 输出为inside，
Blocks
you assign a name to a block,the code in the block is always enclosed within braces({}),always invoked from a function with the same name as that of the block.This means that if you have a block with the nametest,then you use the function nametest to invoke this block.
block_name
{
statement1,
statement2
}
1.9.3-p125 :001 > def test
1.9.3-p125 :002?> puts "you r in the method"
1.9.3-p125 :003?> yield
1.9.3-p125 :004?> puts "you are again back to the method"
1.9.3-p125 :005?> yield
1.9.3-p125 :006?> end
=> nil
1.9.3-p125 :007 > test {p "Fuck"}
you r in the method
"Fuck"
you are again back to the method
"Fuck"
=> "Fuck"
有参数的调用：
def test
yield 5
puts "You are in the method test"
yield 100
end
test {|i| puts "You are in the block #{i}"}
暂时未学习，待补充.
块与方法
