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As there is currently no simple way of combining dictionaries in Swift, it can be useful to overload the + and += operators in order to add this functionality using generics. // Combines two dictionaries together. If both dictionaries contain // the same key, the value of the right hand side dicti...

The SQL 2008 standard defines the FETCH FIRST clause to limit the number of records returned. SELECT Id, ProductName, UnitPrice, Package FROM Product ORDER BY UnitPrice DESC FETCH FIRST 10 ROWS ONLY This standard is only supported in recent versions of some RDMSs. Vendor-specific non-stand...

When NSLog is asked to print empty string, it omits the log completely. NSString *name = @""; NSLog(@"%@", name); // Resolves to @"" The above code will print nothing. It is a good practice to prefix logs with labels: NSString *name = @""; NSLog(@&quo...

The for clause of a list comprehension can specify more than one variable: [x + y for x, y in [(1, 2), (3, 4), (5, 6)]] # Out: [3, 7, 11] [x + y for x, y in zip([1, 3, 5], [2, 4, 6])] # Out: [3, 7, 11] This is just like regular for loops: for x, y in [(1,2), (3,4), (5,6)]: print(x+y) ...

Pojo Model public class Model { private String firstName; private String lastName; private int age; /* Getters and setters not shown for brevity */ } Example: String to Object Model outputObject = objectMapper.readValue( "{\"firstName\":\"J...

ProcedureName ProcedureName argument1, argument2 Call a procedure by its name without any parentheses. Edge case The Call keyword is only required in one edge case: Call DoSomething : DoSomethingElse DoSomething and DoSomethingElse are procedures being called. If the Call keyword was rem...

To retrieve the result of a procedure call (e.g. Function or Property Get procedures), put the call on the right-hand side of an assignment: result = ProcedureName result = ProcedureName(argument1, argument2) Parentheses must be present if there are parameters. If the procedure has no parameter...

Parentheses are used to enclose the arguments of function calls. Using them for procedure calls can cause unexpected problems. Because they can introduce bugs, both at run-time by passing a possibly unintended value to the procedure, and at compile-time by simply being invalid syntax. Run-time Re...

Call ProcedureName Call ProcedureName(argument1, argument2) The explicit call syntax requires the Call keyword and parentheses around the argument list; parentheses are redundant if there are no parameters. This syntax was made obsolete when the more modern implicit call syntax was added to VB. ...

It's possible to attach an object to an existing object as if there was a new property. This is called association and allows one to extend existing objects. It can be used to provide storage when adding a property via a class extension or otherwise add additional information to an existing object. ...

The Objective-C runtime allows you to change the implementation of a method at runtime. This is called method swizzling and is often used to exchange the implementations of two methods. For example, if the methods foo and bar are exchanged, sending the message foo will now execute the implementation...

NSArray *array1 = [NSArray arrayWithObjects:@"one", @"two", @"three", nil]; NSArray *array2 = @[@"one", @"two", @"three"];

HTML5 data-* attributes provide a convenient way to store data in HTML elements. The stored data can be read or modified using JavaScript <div data-submitted="yes" class="user_profile"> … some content … </div> Data attribute structure is data-*, i.e. the n...

You can use the <img> or <object> elements to embed external SVG elements. Setting the height and width is optional but is highly recommended. Using the image element <img src="attention.svg" width="50" height="50"> Using <img> does not allo...

You can split a string into an array of parts, divided by a separator character. NSString * yourString = @"Stack,Exchange,Network"; NSArray * yourWords = [yourString componentsSeparatedByString:@","]; // Output: @[@"Stack", @"Exchange", @"Network&quot...

To search if a String contains a substring, do the following: NSString *myString = @"This is for checking substrings"; NSString *subString = @"checking"; BOOL doesContainSubstring = [myString containsString:subString]; // YES If targeting iOS 7 or OS X 10.9 (or earlier)...

Office Blog - Excel VBA Performance Coding Best Practices Often, best performance is achieved by avoiding the use of Range as much as possible. In this example we read in an entire Range object into an array, square each number in the array, and then return the array back to the Range. This accesse...

typedef double (^Operation)(double first, double second); If you declare a block type as a typedef, you can then use the new type name instead of the full description of the arguments and return values. This defines Operation as a block that takes two doubles and returns a double. The type can b...

Given the following HTML file: index.html <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>React Tutorial</title> <script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.2.1/react.js"></script>...

<link rel="alternate stylesheet" href="path/to/style.css" title="yourTitle"> Some browsers allow alternate style sheets to apply if they are offered. By default they will not be applied, but usually they can be changed through the browser settings: Firefox l...