bluexuemei的专栏

浮点数转换成整数，会强行去掉小数点后面的数字irb(main):017:0>123.45.to_i=> 123整数转换成浮点数，会添加小数点和0irb(main):018:0>123.to_f=> 123.0

Ruby remove substring matching to any element of array

Ruby中将代码块作为参数传入方法的几种方法及其区别这篇文章只是随手写写玩玩的，我对Ruby的Block和Lambda其实理解并不怎么深刻，知识现在够用就差不多了吧。第一种方法最传统了：?123456def f1(a)  yieldaend f1(1){|a| a.to_s}# "1"

Ruby对时间的处理函数1.当前时间 t = Time.new 或 t = Time.now2.生成指定时间  t1 =Time.mktime(2001)               # January 1, 2001 at 0:00:00 t2 = Time.mktime(2001,3) t3 = Time.mktime(2001,3,15) 

ruby正则表达式不支持逆序环视？该怎么解决2012-03-18 来源：读书人网 【读书人网(Reader8.cn)：综合教育门户网站】0ruby正则表达式不支持逆序环视？在《精通正则表达式》一书中，作者介绍了如何使用顺序环视和逆序环视在数值中ruby正则表达式不支持逆序环视？在《精通正则表达式》一书中，作者介绍了如何使用顺序环视和逆序环视在数值中插入逗号：

require "date"today = Date.today(today-7..today).map { |date| date.strftime("%m-%d") }

RegexpRegexp是处理正则表达式的类。正则表达式的字面值是以双斜线内夹表达式的形式生成的。/^this is regexp/还可以使用Regexp.new(string)来动态地生成正则表达式对象。类方法Regexp.compile(string[, option[, code]])Regexp.new(string[, option[, cod

interger to I P addressAaron Gifford astounding at gmail.com Wed Aug 27 17:05:32 CDT 2008Previous message: interger to I P addressNext message: interger to I P addressMessages sorted by:

I have a 2D array as below[[1, 4.0, "burger"], [1, 8.0, "tofu_log"], [2, 5.0, "burger"], [2, 6.5, "tofu_log"]]Here, each element is a collection of restaurant_id, price and item. The task is to re

I am looking to append to a JSON array in ruby. The JSON array looks like this:{"data" : [{"name":"Chris","long":10,"lat":19}, {"name":"Scott","long":9,"lat":18}]}I want to be able to append anoth

'm trying to sort an array of arrays alphabetically at the exclusion of the word "Other", which is a member that I want at the end of the array. Let's say that the array looks like the following:cit

Zip together sub arrays of a 2 dimensional arrayIs there a general way of doing this ?Each sub array will be of the same length.c = [[1,1,1,1], [2,2,2,2], [3,3,3,3]]c[0].zip(c[1], c[2])=

my_array = ["sh.please-word", ".things-to-do" , "#cool-stuff", "span.please-word-not"]

If you want to get each character's index as a hash, this would work:b = %w(A B A A C C B D A D)h = {}b.each_with_index { |e, i| h[e] ||= [] h[e] i}h#=> {"A"=>[0, 2, 3, 8], "B"=>[1, 6], "

how to merge array of hash based same keys in ruby?example :a = [{:a=>1},{:a=>10},{:b=>8},{:c=>7},{:c=>2}]how to get result like this?a = [{:a=>[1, 10]},{:b=>8},{:c=>[7, 2]}]thanks before

I am working in a ruby on rails project where i am creating complex algorithm, i need help regarding adding 2 two dimensional array.i want to do following:array1 = [[1,10],[2,20],[3,10],[4,30]]arr

Especially when working with structs, it would be nice to be able to call a different method per each element in an array, something like this:array = %w{name 4 tag 0.343}array.convert(:to_s, :to_i

I'd like to convert from{'key1' => (1..10) , 'key2' => (11..20) , 'key3' => (21..30)}to[{'key1' => 1, 'key2' => 11, 'key3' => 21},{'key1' => 1, 'key2' => 11, 'key3' => 22},... . .{'key1' =

I've got an array of hashes and would like to sum up selected values. I know how to sum all of them or one of them but not how to select more than one key.i.e.:[{"a"=>5, "b"=>10, "active"=>"yes"},

ar = [1, 2, 3, 5, 6, 8, 9]prev = ar[0]p ar.slice_before { |e| prev, prev2 = e, prev prev2 + 1 != e}.map{|a| a[0]..a[-1]} # >> [1..3, 5..6, 8..9]ar = [1, 2, 3, 5, 6,7, 8, 9,11]prev = ar[0]p

Basically I'm trying to condense this one array of hashes with the same value into another array. I'm new to Ruby and I'm trying to change thisfruit = [ {type: 'grape', color: 'purple' }, {type: '

I have two arrays one = [1,2,3,4,5,6,7] and two = [{1=>'10'},{3=>'22'},{7=>'40'}]Two will have one.length hashes or less. I want a new array of values from two if it's key appears in one, if not the

(0..12).map { |i| "rate_limit_%03d" % i }# => ["rate_limit_000", "rate_limit_001", "rate_limit_002", ...

["ABC", "DEF", "GHI"]should generate["ADG", "ADH", "ADI", "AEG", "AEH", "AEI", "AFG", "AFH", "AFI", "BDG", "BDH", "BDI", "BEG", "BEH", "BEI", "BFG", "BFH", "BFI", "CDG", "CDH", "CDI", "CEG", "CE

def createPhoneNumber(numbers) "(#{numbers[0..2].join}) #{numbers[3..5].join}-#{numbers[6..9].join}"end

For instance, if I have this array: [ 0, 5, 4, 7, 1 ]I need to change it to: [ '', '', '', '', '']Enumerable#map replaces every element with the result of calling a block:array = [ 0, 5, 4, 7,

Just out of curiosity:def two_sum? a a.count(0) > 1 || (a & a.map(&:-@)).size > 1endtwo_sum? [1,2,3,4,-2] # ⇒ truetwo_sum? [1,0,3,4,0] # ⇒ truetwo_sum? [1,2,3,4,0] # ⇒ falsetwo_sum? [1,2,

Since your example includes 000 which can only be a string (000 asFixnum is rendered as 0) you can easily split your numbers in group of 3 digits by doing:num = 10000 # your numres = num.to_s.rev

I have an array a = [1,2,3,4,5]. I want to test which of the numbers areprime and wanted to produce the output {1=>false, 2=>true, 3=>true, 4=>false, 5=>true}.Any one liner will be appreciated.

This may be very simple, but I don't know all of Ruby's array functions.If I have a given array like:values = [["a", 1], ["b", 3], ["c", 7], ... etc ]I would like two functions:A function th

No need the custom_merge method. Ruby core supplied Hash#merge with block will help you out.h1 = {a: 1, c: 2} h2 = {a: 3, b: 5} h3 = h1.merge(h2){|k,o,n| [o,n]}h3# => {:a=>[1, 3], :c=>2, :b=>5

I have an array like this:inList = ["edge_rabbit", "nsp_edge_rabbit", "services", "syslog", "master_rabbit", "mongod", ...]How can I take the elements that end with _rabbit or elements with the fo

Lets say I have an array like so:['x','cat', 'dog', 'x', 'dolphin', 'cougar', 'whale']I don't know the length of the array or when an 'x' will occur. When I reach 'x' I want to push the following el

I need to add consecutive numbers to a new array and, if it is not a consecutive number, add only that value to a new array:old_array = [1, 2, 3, 5, 7, 8, 9, 20, 21, 23, 29]I want to get this resu

a=["one", "two", "three"]b=["two", "one", "three"]

Let's say I have an Array ary = [0.0, 1.0, 5.0, 1.0, -2.0, 3.5], and I want as output another array of the same size containingary's indices in sorted-by-value-order. In other words, the output shou

arr1 = [{ "device"=>100, "phone"=>"12345" },{ "device"=>102, "phone"=>"12346" }]arr2 = [{ "device"=>100, "type"=>"mobile", "name"=>"nokia" },{ "device"=>102, "type"=>"VIOP", "name"=>"smth" }]-----

I'm trying to count the occurrences of elements in an array and save it in a hash. I'd like to use the inject function. I have this code:a = ["the","the","a", "it", "it", "it"]a.inject(Hash.new(0))

I have a hash mapping array indices to sort values, e.g.{0=>"item_ss", 1=>"item_hsj", 2=>"item_skls"}I have a separate array with line_item_id and associated line_items (tab separated) as foll

ruby字符串的encoding,force_encoding,encode,encode! 19 May 2013 ruby1.9开始对字符串编码支持已经比较完善，我们可以直接通过使用String类的实例方法 encoding,force_encoding,encode,encode!进行相关的编码操作。encodingruby1.9中为每个字符串对象增加了encodin