logical-operators

In Ruby you can easily set a default value for a variable x ||= "default" The above statement will set the value of x to "default" if x is nil or false Is there a similar shortcut in PHP or do I have to use the longer form: $x = (isset($x))? $x : "default"; Are there any easier ways to handle this in PHP? As of PHP 5.3 you can use the ternary operator while omitting the middle argument: $x = $x ?: 'default'; isset($x) or $x = 'default'; As of PHP 7.0, you can also use the null coalescence operator // PHP version < 7.0, using a standard ternary $x = (isset($_GET['y'])) ? $_GET['y'] : 'not set';

When I for instance write 7>1 in C (say C99 if this is not an always-been feature), can I expect the result will be exactly 1 or just some non-zero value? Does this hold for all bool operators? In C99 §6.5.8 Relational Operators, item 6 ( < , > , <= and >= ): Each of the operators < (less than), > (greater than), <= (less than or equal to), and >= (greater than or equal to) shall yield 1 if the specified relation is true and 0 if it is false) The result has type int . As for equality operators, it's a bit further in §6.5.9 ( == and != ): The == (equal to) and != (not equal to) operators are

1). var bitValue = (byteValue & (1 << bitNumber)) != 0; 2). using System.Collections.BitArray with a Get(int index) method What is faster? In what situations for the .NET projects BitArray could be more useful than a simple conjunction with the bitwise shift? BitArray is going to be able to handle an arbitrary number of boolean values, whereas a byte will hold only 8, int only 32, etc. This is going to be the biggest difference between the two. Also, BitArray implements IEnumerable , where a integral type obviously does not. So it all depends on the requirements of your project; if you need an

Is there a difference in the way SQL interprets the logical operators AND and && ? For mySQL: The manual is not saying it explicitly, but they are listed as identical: AND, && Logical AND. Evaluates to 1 if all operands are nonzero and not NULL, to 0 if one or more operands are 0, otherwise NULL is returned. The operator precedence page also makes no distiction. AND is Standard SQL && is proprietary syntax According to this page http://msdn.microsoft.com/en-us/library/bb387129.aspx they have the same functionality in SQL Server. MySql has this to say on the subject http://dev.mysql.com/doc

Ok, so I've read about this a number of times, but I'm yet to hear a clear, easy to understand (and memorable) way to learn the difference between: if (x | y) and if (x || y) ..within the context of C#. Can anyone please help me learn this basic truth, and how C# specifically, treats them differently (because they seem to do the same thing). If the difference a given piece of code has between them is irrelevant, which should I default to as a best-practise? John Feminella || is the logical-or operator. See here . It evaluates to true if at least one of the operands is true. You can only use it