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What is the difference between $(command) and `command` in shell programming?
...ommand substitution because $() can easily nest within itself as in $(echo foo$(echo bar)). There are other differences such as how backslashes are parsed in the backtick/gravemark version, etc.
See BashFAQ/082 for several reasons to always prefer the $(...) syntax.
Also see the POSIX spec for d...
How to avoid “if” chains?
...
Just use an additional function to get your second version to work:
void foo()
{
bool conditionA = executeStepA();
if (!conditionA) return;
bool conditionB = executeStepB();
if (!conditionB) return;
bool conditionC = executeStepC();
if (!conditionC) return;
}
void bar()
{
foo();
...
How to include another XHTML in XHTML using JSF 2.0 Facelets?
...plate page /WEB-INF/template.xhtml (as a design hint: the header, menu and footer can in turn even be <ui:include> files):
<!DOCTYPE html>
<html lang="en"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://xmlns.jcp.org/jsf/core"
xmlns:h="http://xmlns.jcp.org/jsf/html"
...
What does static_assert do, and what would you use it for?
...ry::Version > 2,
"Old versions of SomeLibrary are missing the foo functionality. Cannot proceed!");
class UsingSomeLibrary {
// ...
};
Assuming that SomeLibrary::Version is declared as a static const, rather than being #defined (as one would expect in a C++ library).
Contrast wi...
JavaScript object: access variable property by name as string [duplicate]
...enced through multiple brackets. If you have a nested object like so:
var foo = { a: 1, b: 2, c: {x: 999, y:998, z: 997}};
you can access property x of c as follows:
var cx = foo['c']['x']
If a property is undefined, an attempt to reference it will return undefined (not null or false):
foo['c...
Getter and Setter?
...y is of a specific type without using setters.
In PHP, this works:
class Foo {
public $bar; // should be an integer
}
$foo = new Foo;
$foo->bar = "string";
In Java, it doesn't:
class Foo {
public int bar;
}
Foo myFoo = new Foo();
myFoo.bar = "string"; // error
Using magic methods (__...
How to check if element has any children in Javascript?
...log(
isEmpty("#one"), // false
isEmpty("#two"), // true
isEmpty(".foo"), // false
isEmpty(".bar") // true
);
<div id="one">
foo
</div>
<div id="two">
</div>
<div class="foo"></div>
<div class="foo"><p>foo</p></div&...
Check if object exists in JavaScript
...null !== undefined gives you what you might expect. Please also note, that foo != null can be an effective way to check if a variable is neither undefined nor null. Of course you can be explicit, because it may help readability.
If you restrict the question to check if an object exists, typeof o ==...
CSS selector for “foo that contains bar”? [duplicate]
Is there a way to make a CSS Selector that matches the following?
3 Answers
3
...
Understanding events and event handlers in C#
... return void and take a string.
public delegate void MyEventHandler(string foo);
//This event can cause any method which conforms
//to MyEventHandler to be called.
public event MyEventHandler SomethingHappened;
//Here is some code I want to be executed
//when SomethingHappened fires.
void HandleSo...