Array#step

hack ruby系列。。。。

class Array
  def step(n)
    if block_given?
      (0..size).step(n) {|i| yield self[i]}
    else
      raise ArgumentError
    end
  end
end

[1,2,3,4,5].step(2) do |i|
  puts i
end

# => 1, 3, 5

继续hack

class Float
  def four_remove_and_five_pass(n)#四射五入...请原谅哥的poor English..
    wei = Array.new(n,10).inject(1){|sum,i| sum*i}
    (self * wei).round / wei.to_f 
  end
end

puts 1.5555.four_remove_and_five_pass(3)#保留3位小数=>1.55

评论

1 楼 全冠清 2009-08-15  

Array.prototype.step=function(n,fn_s){
  var i=0;
  do{
  	fn_s(this[i]);
    i+=n
  }while(i<=this.length)
}
var a=[0,1,2,3,4,5,6,7,8]
a.step(2,function(j){document.writeln(j+'<br>')})