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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...

Some websites don’t like to be scraped. In these cases you may need to simulate a real user working with a browser. Selenium launches and controls a web browser. from selenium import webdriver browser = webdriver.Firefox() # launch firefox browser browser.get('http://stackoverflow.com/questi...

To get a difference between two Calendars, use getTimeInMillis() method: Calendar c1 = Calendar.getInstance(); Calendar c2 = Calendar.getInstance(); c2.set(Calendar.DATE, c2.get(Calendar.DATE) + 1); System.out.println(c2.getTimeInMillis() - c1.getTimeInMillis()); //outputs 86400000 (24 * 60 * ...

The Abstract Factory Pattern is a creational design pattern that can be used to define specific instances or classes without having to specify the exact object that is being created. function Car() { this.name = "Car"; this.wheels = 4; } function Truck() { this.name = "Truck"; ...

MySQL allows to specify from which table the matching rows must be deleted -- remove only the employees DELETE e FROM Employees e JOIN Department d ON e.department_id = d.department_id WHERE d.name = 'Sales' -- remove employees and department DELETE e, d FROM Emp...

"MySQL Cluster" disambiguation... NDB Cluster -- A specialized, mostly in-memory, engine. Not widely used. Galera Cluster aka Percona XtraDB Cluster aka PXC aka MariaDB with Galera. -- A very good High Availability solution for MySQL; it goes beyond Replication. See individual page...

Limit root (and any other SUPER-privileged user) to GRANT ... TO root@localhost ... That prevents access from other servers. You should hand out SUPER to very few people, and they should be aware of their responsibility. The application should not have SUPER. Limit application logins to the one...

// Usage: var p0={x:50,y:100}; var p1={x:100,y:0}; var p2={x:200,y:200}; var p3={x:300,y:100}; cubicCurveArrowHeads(p0, p1, p2, p3, 15, true, true); quadraticCurveArrowHeads(p0, p1, p2, 15, true, true); // or use defaults true for both ends with arrow heads cubicCurveArrowHeads(p0, p...

// Usage: var arc={ cx:150, cy:150, innerRadius:75, outerRadius:100, startAngle:-Math.PI/4, endAngle:Math.PI } drawArc(arc,'skyblue','gray',4); function drawArc(a,fill,stroke,strokewidth){ ctx.beginPath(); ctx.arc(a.cx,a.cy,a.innerRadius,a.startAngle,a.endAngle); ...

When Canvas draws a line it automatically adds anti-aliasing to visually heal "jaggedness". The result is a line that is less jagged but more blurry. This function draws a line between 2 points without anti-aliasing using Bresenham's_line algorithm. The result is a crisp line without the ...

<?xml version="1.0" encoding="utf-8"?> <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx"> <s:Label text="Hello World!&...

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...

Run interactive vim tutorials as many times as needed to feel comfortable with the basics. Vim features several modes, e.g. normal mode, insert mode and command-line mode. Normal mode is for editing and navigating text. In this mode h, j, k and l correspond to the cursor keys ←, ↓, ↑ and →. Most 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...

%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...

With the bind command it is possible to define custom key bindings. The next example bind an Alt + w to >/dev/null 2>&1: bind '"\ew"':"\" >/dev/null 2>&1\"" If you want to execute the line immediately add \C-m (Enter) to it: bind '"\ew&quo...

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...

NSMutableDictionary *attributesDictionary = [NSMutableDictionary dictionary]; [attributesDictionary setObject:[UIFont systemFontOfSize:14] forKey:NSFontAttributeName]; //[attributesDictionary setObject:[UIColor redColor] forKey:NSForegroundColorAttributeName]; NSMutableAttributedString *attri...

Validation attributes are used to enforce various validation rules in a declarative fashion on classes or class members. All validation attributes derive from the ValidationAttribute base class. Example: RequiredAttribute When validated through the ValidationAttribute.Validate method, this att...

Information about the database connections SELECT a.mon$attachment_id as Attachment_ID, a.mon$server_pid as Server_PID, case a.mon$state when 1 then 'active' when 0 then 'idle' end as State, a.mon$attachment_name as Database_Name, ...