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Inheriting class methods from modules / mixins in Ruby
...ors of the class. You can look at the ancestors of any class or module by calling its ancestors method:
module M
def foo; "foo"; end
end
class C
include M
def bar; "bar"; end
end
C.ancestors
#=> [C, M, Object, Kernel, BasicObject]
# ^ look, it's right here!
When you call a metho...
How to use if - else structure in a batch file?
...stion about if - else structure in a batch file. Each command runs individually, but I couldn't use "if - else" blocks safely so these parts of my programme doesn't work. How can I do make these parts run? Thank you.
...
What does = +_ mean in JavaScript
...s to a number.
_ is only a variable name (not an operator), it could be a, foo etc.
Example:
+"1"
cast "1" to pure number 1.
var _ = "1";
var r = +_;
r is now 1, not "1".
Moreover, according to the MDN page on Arithmetic Operators:
The unary plus operator precedes its operand and evalua...
Why does the Scala compiler disallow overloaded methods with default arguments?
... such method overloadings could become ambiguous, why does the compiler disallow code which is neither ambiguous at compile time nor at run time?
...
How to test that no exception is thrown?
... test your functionality: if an exception is thrown the test will automatically fail. If no exception is thrown, your tests will all turn up green.
I have noticed this question garners interest from time to time so I'll expand a little.
Background to unit testing
When you're unit testing it's imp...
Best practice for Django project working directory structure
I know there is actually no single right way. However I've found that it's hard to create a directory structure that works well and remain clean for every developer and administrator. There is some standard structure in most projects on github. But it does not show a way to organize another files an...
jquery selector for id starts with specific text [duplicate]
...re 'attribute' ends with 'Dialog'
$("[attribute$='Dialog']");
// Selects all divs where attribute is NOT equal to value
$("div[attribute!='value']");
// Select all elements that have an attribute whose value is like
$("[attribute*='value']");
// Select all elements that have an attribute w...
Connect Java to a MySQL database
...
Here's a step by step explanation how to install MySQL and JDBC and how to use it:
Download and install the MySQL server. Just do it the usual way. Remember the port number whenever you've changed it. It's by default 3306.
Download the JDBC driver and put in classpath...
Why doesn't 'ref' and 'out' support polymorphism?
...nswer as the basis for this blog entry:
Why do ref and out parameters not allow type variation?
See the blog page for more commentary on this issue. Thanks for the great question.
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Let's suppose you have classes Animal, Mammal, Reptile, Giraffe, Turtle and Tiger, with the obvious s...
Remove substring from the string
...
@bcackerman -- delete wouldn't work, since it deletes all the characters you pass in: 'hello world'.delete('hello') #=> ' wrd'
– rusty
Jun 2 '15 at 14:55
...