Yes!  This is possible now in Ruby 2.0.0.  One way to write it is:

    %i{foo bar}  # =&gt; [:foo, :bar]

You can also use other delimiters, so you could also write `%i(foo bar)` or `%i!foo bar!` for example.

This feature was originally announced here:

http://www.ruby-lang.org/zh_TW/news/2012/11/02/ruby-2-0-0-preview1-released/

It is mentioned in the official documentation of Ruby here:

http://ruby-doc.org/core/doc/syntax/literals_rdoc.html#label-Percent+Strings

In Ruby 1.x, unfortunately the list of available [%-delimiters][1] is limited



    Modifier	Meaning
    %q[ ]		Non-interpolated String (except for \\ \[ and \])
    %Q[ ]		Interpolated String (default)
    %r[ ]		Interpolated Regexp (flags can appear after the closing delimiter)
    %s[ ]		Non-interpolated Symbol
    %w[ ]		Non-interpolated Array of words, separated by whitespace
    %W[ ]		Interpolated Array of words, separated by whitespace
    %x[ ]		Interpolated shell command

  [1]: http://en.wikibooks.org/wiki/Ruby_Programming/Syntax/Literals#The_.25_Notation

I know how to remove an entry, `&#39;key&#39;` from my dictionary `d`, safely. You do:

    if d.has_key(&#39;key&#39;):
        del d[&#39;key&#39;]

However, I need to remove multiple entries from a dictionary safely.  I was thinking of defining the entries in a tuple as I will need to do this more than once.

    entities_to_remove = (&#39;a&#39;, &#39;b&#39;, &#39;c&#39;)
    for x in entities_to_remove:
        if x in d:
            del d[x]

However, I was wondering if there is a smarter way to do this?

Removing multiple keys from a dictionary safely

I want to trim a string if the length exceeds 10 characters.

Suppose if the string length is 12 (`String s=&quot;abcdafghijkl&quot;`), then the new trimmed string will contain `&quot;abcdefgh..&quot;`.

How can I achieve this?

Trim a string based on the string length

I like this literal expression for an array of strings:

    %w( i can easily create arrays of words )

I am wondering if there is a literal to get an array of symbols. I know I can do 

    %w( it is less elegant to create arrays of symbols ).map( &amp;:to_sym )

but it would be so wonderful just to use a literal.

Is there a literal notation for an array of symbols?

I like this literal expression for an array of strings:
<pre><code class="hljs language-scss">%w( i can easily create arrays of words )
</code></pre>
I am wondering if there is a literal to get an array of symbols. I know I can do
<pre><code class="hljs language-scss">%w( it is less elegant to create arrays of symbols ).map( &#x26;:to_sym )
</code></pre>
but it would be so wonderful just to use a literal.

I have a large hash with nested arrays and hashes.  I would like to simply print it out so it &#39;readable&#39; to the user.

I would like it to be sort of like to_yaml - that&#39;s pretty readable - but still too tech looking.  

Ultimately its going to be end users who need to read these data chunks so they need to be formatted cleanly.

Any suggestions?

Best way to pretty print a hash

In Rails MVC, can you call a controller&#39;s method from a view (as a method could be called call from a helper)? If yes, how?


Can we call a Controller&#39;s method from a view (as we call from helper ideally)?

`arr` is array of strings:

    [&quot;hello&quot;, &quot;world&quot;, &quot;stack&quot;, &quot;overflow&quot;, &quot;hello&quot;, &quot;again&quot;]

What would be an easy and elegant way to check if `arr` has duplicates, and if so, return one of them (no matter which)?

Examples:

    [&quot;A&quot;, &quot;B&quot;, &quot;C&quot;, &quot;B&quot;, &quot;A&quot;]    # =&gt; &quot;A&quot; or &quot;B&quot;
    [&quot;A&quot;, &quot;B&quot;, &quot;C&quot;]              # =&gt; nil

How to find and return a duplicate value in array

Let&#39;s say I am trying to remove elements from array `a = [1,1,1,2,2,3]`. If I perform the following:

    b = a - [1,3]
Then I will get:

    b = [2,2]
However, I want the result to be

    b = [1,1,2,2]
i.e. I only remove one instance of each element in the subtracted vector not all cases. Is there a simple way in Ruby to do this?

Removing elements from array Ruby

I must be overlooking something very simple here but I can&#39;t seem to figure out how to render a simple ERB template with values from a hash-map.

I am relatively new to ruby, coming from python. I have an ERB template (not HTML), which I need rendered with context that&#39;s to be taken from a hash-map, which I receive from an external source.

However, the documentation of ERB, states that the `ERB.result` method takes a `binding`. I learnt that they are something that hold the variable contexts in ruby (something like `locals()` and `globals()` in python, I presume?). But, I don&#39;t know how I can build a binding object out of my hash-map.

A little (a *lot*, actually) googling gave me this: http://refactormycode.com/codes/281-given-a-hash-of-variables-render-an-erb-template, which uses some ruby metaprogramming magic that escapes me.

So, isn&#39;t there a simple solution to this problem? Or is there a better templating engine (not tied to HTML) better suited for this? (I only chose ERB because its in the stdlib).

Render an ERB template with values from a hash

I have an array of objects with several key value pairs, and I need to sort them based on &#39;updated_at&#39;:

    [
        {
            &quot;updated_at&quot; : &quot;2012-01-01T06:25:24Z&quot;,
            &quot;foo&quot; : &quot;bar&quot;
        },
        {
            &quot;updated_at&quot; : &quot;2012-01-09T11:25:13Z&quot;,
            &quot;foo&quot; : &quot;bar&quot;
        },
        {
            &quot;updated_at&quot; : &quot;2012-01-05T04:13:24Z&quot;,
            &quot;foo&quot; : &quot;bar&quot;
        }
    ]

What&#39;s the most efficient way to do so?

Sort array of objects by single key with date value

I&#39;ve looked around the internet and haven&#39;t quite found what I&#39;m looking for. I have a flat array with each element containing an &#39;id&#39; and a &#39;parent_id&#39;. Each element will only have ONE parent, but may have multiple children. If the parent_id = 0, it is considered a root level item. I&#39;m trying to get my flat array into a tree. The other samples I have found only only copy the element to the parent, but the original still exists.

**EDIT**

Each element of the starting array is read from a separate XML file. The file itself will have &#39;0&#39; as the value for parent_id if it doesn&#39;t have a parent. The keys are actually strings.

I&#39;m sorry for the confusion earlier. Hopefully this is more clear:

**/EDIT**

My starting array:

&lt;pre&gt;
Array
(
    [_319_] =&gt; Array
        (
            [id] =&gt; 0
            [parent_id] =&gt; 0
        )

    [_320_] =&gt; Array
        (
            [id] =&gt; _320_
            [parent_id] =&gt; 0
        )

    [_321_] =&gt; Array
        (
            [id] =&gt; _321_
            [parent_id] =&gt; _320_
        )

    [_322_] =&gt; Array
        (
            [id] =&gt; _322_
            [parent_id] =&gt; _321_
        )

    [_323_] =&gt; Array
        (
            [id] =&gt; _323_
            [parent_id] =&gt; 0
        )

    [_324_] =&gt; Array
        (
            [id] =&gt; _324_
            [parent_id] =&gt; _323_
        )

    [_325_] =&gt; Array
        (
            [id] =&gt; _325_
            [parent_id] =&gt; _320_
        )
)&lt;/pre&gt;

The resulting array after the tree is made:

&lt;pre&gt;
Array
(
    [_319_] =&gt; Array
        (
            [id] =&gt; _319_
            [parent_id] =&gt; 0
        )

    [_320_] =&gt; Array
        (
            [id] =&gt; _320_
            [parent_id] =&gt; 0
            [children] =&gt; Array
                (
                    [_321_] =&gt; Array
                        (
                            [id] =&gt; _321_
                            [parent_id] =&gt; _320_
                            [children] =&gt; Array
                                (
                                    [_322_] =&gt; Array
                                        (
                                            [id] =&gt; _322_
                                            [parent_id] =&gt; _321_
                                        )
                                )
                        )
                    [_325_] =&gt; Array
                        (
                            [id] =&gt; _325_
                            [parent_id] =&gt; _320_
                        )
                )
    [_323_] =&gt; Array
        (
            [id] =&gt; _323_
            [parent_id] =&gt; 0
            [children] =&gt; Array
                (
                    [_324_] =&gt; Array
                        (
                            [id] =&gt; _324_
                            [parent_id] =&gt; _323_
                        )
                )
        )
&lt;/pre&gt;

Any help / guidance is greatly appreciated!

Some code I have so far:

&lt;pre&gt;

        function buildTree(array &amp;$elements, $parentId = 0) {
        $branch = array();
    
        foreach ($elements as $element) {
            if ($element[&#39;parent_id&#39;] == $parentId) {
                $children = $this-&gt;buildTree($elements, $element[&#39;id&#39;]);
                if ($children) {
                    $element[&#39;children&#39;] = $children;
                }
                $branch[] = $element;
            }
        }
    
        return $branch;
    }

&lt;/pre&gt;

Build a tree from a flat array in PHP

The following code gives me error 9 &quot;subscript out of range&quot;. I meant to declare a dynamic array so that the dimension changes as I add elements to it. Do I have to create a &quot;spot&quot; on the array before I store something in it like in JS?


    Sub test_array()
        Dim test() As Integer
        Dim i As Integer
        For i = 0 To 3
            test(i) = 3 + i
        Next i
    End Sub

Populating VBA dynamic arrays

I have an array of objects and I want to compare those objects on a specific object property. Here&#39;s my array:

    var myArray = [
        {&quot;ID&quot;: 1, &quot;Cost&quot;: 200},
        {&quot;ID&quot;: 2, &quot;Cost&quot;: 1000},
        {&quot;ID&quot;: 3, &quot;Cost&quot;: 50},
        {&quot;ID&quot;: 4, &quot;Cost&quot;: 500}
    ]

I&#39;d like to zero in on the &quot;cost&quot; specifically and a get a min and maximum value. I realize I can just grab the cost values and push them off into a javascript array and then run the [Fast JavaScript Max/Min][1].

However is there an easier way to do this by bypassing the array step in the middle and going off the objects properties (in this case &quot;Cost&quot;) directly?


  [1]: http://ejohn.org/blog/fast-javascript-maxmin/ &quot;Fast JavaScript Max/Min&quot;





Compare JavaScript Array of Objects to Get Min / Max

I want to write a script that loops through 15 strings (array possibly?) Is that possible?

Something like:

    for databaseName in listOfNames
    then
      # Do something
    end


Loop through an array of strings in Bash?

What does `::=` mean in programming documentation?
&lt;br /&gt;For example in the [Lua documentation][1]: or in [Python documentation][2].


  [1]: http://www.lua.org/manual/5.2/manual.html#3.2
  [2]: http://docs.python.org/release/2.7.1/reference/lexical_analysis.html#identifiers

What does a double colon followed by an equals sign (::=) mean in programming documentation?

I have a problem. I have found the HTML code for the downwards arrow, `&amp;darr;` (&amp;darr;)

Cool. Now I need to use it in CSS like so:

    nav a:hover {content:&quot;&amp;darr&quot;;}

That obviously won&#39;t work since `&amp;darr;` is an HTML symbol. There seems to be less info about these &quot;escaped unicode&quot; symbols that are used in css. There are other symbols like `\2020` that I found but no arrows. What are the arrow codes?


Placing Unicode character in CSS content value

How should I encode special characters into web pages? For instance I need this symbol ℃, which I used just by copying and pasting the character as I can see it now. This worked for the desktop browsers I checked with and also on iPad and iPhone but nothing is displayed on a Blackberry I used for testing. Is there a standard best practice for this? 

http://www.fileformat.info/info/unicode/char/2103/browsertest.htm

Best way to encode Degree Celsius symbol into web page?

Unicode has a million icon-like glyphs, but they&#39;re very hard to search.

Is there a Unicode glyph that looks like a &quot;Binocular&quot; or &quot;magnifying glass&quot;?
Or is there a symbol that&#39;s used to mean &quot;Search&quot;, which is in Unicode?

Is there Unicode glyph Symbol to represent &quot;Search&quot;

I am learning rails and following [this thread](https://stackoverflow.com/questions/1961030). I am stuck with the `to_proc` method. I consider symbols only as alternatives to strings (they are like strings but cheaper in terms of memory). If there is anything else I am missing for symbols, then please tell me. Please explain in simple way what `to_proc` means and what it is used for.

What does to_proc method mean?

As I&#39;ve understood it there are two ways to do a Python decorator, to either use the `__call__` of a class or to define and call a function as the decorator. What&#39;s the advantages/disadvantages of these methods? Is there one preferred method?

Example 1

    class dec1(object):
        def __init__(self, f):
            self.f = f
        def __call__(self):
            print &quot;Decorating&quot;, self.f.__name__
            self.f()

    @dec1
    def func1():
        print &quot;inside func1()&quot;

    func1()

    # Decorating func1
    # inside func1()


Example 2

    def dec2(f):
        def new_f():
            print &quot;Decorating&quot;, f.__name__
            f()
        return new_f

    @dec2
    def func2():
        print &quot;inside func2()&quot;

    func2()

    # Decorating func2
    # inside func2()

Python decorator best practice, using a class vs a function

I&#39;ve been puzzling about this for a while and I&#39;ve looked around a bit, unable to find any discussion about the subject.

Lets assume I wanted to implement a trivial example, like a new looping construct: do..until

Written very similarly to do..while

    do {
        //Things happen here
    } until (i == 15)

This could be transformed into valid csharp by doing so:

    do {
        //Things happen here
    } while (!(i == 15))

This is obviously a simple example, but is there any way to add something of this nature?  Ideally as a Visual Studio extension to enable syntax highlighting etc.

Content Type	Original Author	Original Content on Stackoverflow
Question	m_x	View Question on Stackoverflow
Solution 1 - Ruby	David Grayson	View Answer on Stackoverflow
Solution 2 - Ruby	Gareth	View Answer on Stackoverflow

Is there a literal notation for an array of symbols?

Ruby Problem Overview

Ruby Solutions

Solution 1 - Ruby

Solution 2 - Ruby

Trim a string based on the string length

Removing multiple keys from a dictionary safely

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