Tutorial by Examples: re

Ruby offers define_method as a private method on modules and classes for defining new instance methods. However, the 'body' of the method must be a Proc or another existing method. One way to create a method from raw string data is to use eval to create a Proc from the code: xml = <<ENDXML ...

If you want to xcopy files with specific type to a new folder keeping the current folder structure you need only to do this xcopy [SourcePath]*.mp3 [DestinationPath] /sy

By Default, powershell would return the output to the calling Entity. Consider Below Example, Get-Process -Name excel This would simply, return the running process which matches the name excel, to the calling entity. In this case, the PowerShell Host. It prints something like, Handles NPM(K...

String Strings are created by wrapping the text with double quotes. Double-quoted strings can evalute variables and special characters. $myString = "Some basic text" $mySecondString = "String with a $variable" To use a double quote inside a string it needs to be escaped usi...

var record = nlapiCreateRecord('task'); record.setFieldValue('title', taskTitle); var id = nlapiSubmitRecord(record, true);

A regular polygon has all sides equal length. // Usage: drawRegularPolygon(3,25,75,50,6,'gray','red',0); drawRegularPolygon(5,25,150,50,6,'gray','gold',0); drawRegularPolygon(6,25,225,50,6,'gray','lightblue',0); drawRegularPolygon(10,25,300,50,6,'gray','lightgreen',0); function drawRegular...

Before you start the cherry-pick process, you can check if the commit you want to cherry-pick already exists in the target branch, in which case you don't have to do anything. git branch --contains <commit> lists local branches that contain the specified commit. git branch -r --contains <...

Bounded type parameters allow you to set restrictions on generic type arguments: class SomeClass { } class Demo<T extends SomeClass> { } But a type parameter can only bind to a single class type. An interface type can be bound to a type that already had a binding. This is achieve...

The common modifier to ignore case is i: /fog/i will match Fog, foG, etc. The inline version of the modifier looks like (?i). Notes: In Java, by default, case-insensitive matching assumes that only characters in the US-ASCII charset are being matched. Unicode-aware case-insensitive matching c...

The modifier that allows using whitespace inside some parts of the pattern to format it for better readability and to allow comments starting with #: /(?x)^ # start of string (?=\D*\d) # the string should contain at least 1 digit (?!\d+$) # the string cannot consist of digi...

This is a .NET regex specific modifier expressed with n. When used, unnamed groups (like (\d+)) are not captured. Only valid captures are explicitly named groups (e.g. (?<name> subexpression)). (?n)(\d+)-(\w+)-(?<id>\w+) will match the whole 123-1_abc-00098, but (\d+) and (\w+) won't...

The PCRE-compliant PCRE_DOLLAR_ENDONLY modifier that makes the $ anchor match at the very end of the string (excluding the position before the final newline in the string). /^\d+$/D is equal to /^\d+\z/ and matches a whole string that consists of 1 or more digits and will not match "123...

Another PCRE-compliant modifier expressed with /A modifier. If this modifier is set, the pattern is forced to be "anchored", that is, it is constrained to match only at the start of the string which is being searched (the "subject string"). This effect can also be achieved by ap...

The PCRE-compliant PCRE_UNGREEDY flag expressed with /U. It switches greediness inside a pattern: /a.*?b/U = /a.*b/ and vice versa.

One more PCRE modifier that allows the use of duplicate named groups. NOTE: only inline version is supported - (?J), and must be placed at the start of the pattern. If you use /(?J)\w+-(?:new-(?<val>\w+)|\d+-empty-(?<val>[^-]+)-collection)/ the "val" group values will be ...

A PCRE modifier that causes an error if any backslash in a pattern is followed by a letter that has no special meaning. By default, a backslash followed by a letter with no special meaning is treated as a literal. E.g. /big\y/ will match bigy, but /big\y/X will throw an exception. Inline v...

%storemagic stores variables and macros on IPython's database. To automatically restore stored variables at startup add this to ipython_config.py: c.StoreMagic.autorestore = True Example: In [1]: l = ['hello',10,'world'] In [2]: %store l In [3]: exit (IPython session is closed and started...

The arrayref for @foo is \@foo. This is handy if you need to pass an array and other things to a subroutine. Passing @foo is like passing multiple scalars. But passing \@foo is a single scalar. Inside the subroutine: xyz(\@foo, 123); ... sub xyz { my ($arr, $etc) = @_; print $arr-&g...

To unregister from Remote Notifications programatically you can use Objective-C [[UIApplication sharedApplication] unregisterForRemoteNotifications]; Swift UIApplication.sharedApplication().unregisterForRemoteNotifications() this is similar to going into the setting of your phone and manual...

Task that return a value has return type of Task< TResult > where TResult is the type of value that needs to be returned. You can query the outcome of a Task by its Result property. Task<int> t = Task.Run(() => { int sum = 0; for(int i = 0; i < 500; i++) ...