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Prefer composition over inheritance?
... languages would provide a keyword to refer to "this class", and provide a means of defining a class which should behave just like another class, but not be substitutable for it (such a class would have all "this class" references replaced with itself).
– supercat
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What does yield mean in PHP?
I've recently stumbled over this code:
8 Answers
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java.net.ConnectException: Connection refused
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This exception means that there is no service listening on the IP/port you are trying to connect to:
You are trying to connect to the wrong IP/Host or port.
You have not started your server.
Your server is not listening for connections.
O...
What's the rationale for null terminated strings?
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@calavera: But it could have just as simply meant "Create a memory buffer with this string content and a two byte length prefix",
– Billy ONeal
Dec 11 '10 at 20:28
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Are custom elements valid HTML5?
... Chrome and Opera, and becoming available in other browsers. It provides a means to register custom elements in a formal manner.
Custom elements are new types of DOM elements that can be defined by
authors. Unlike decorators, which are stateless and ephemeral, custom
elements can encapsulate state ...
Return 0 if field is null in MySQL
...(SELECT SUM(uop.price * uop.qty) FROM uc_order_products uop WHERE uo.order_id = uop.order_id) AS products_subtotal, 0)?
– Kevin
Oct 22 '10 at 13:46
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querySelector, wildcard element match?
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[id^='someId'] will match all ids starting with someId.
[id$='someId'] will match all ids ending with someId.
[id*='someId'] will match all ids containing someId.
If you're looking for the name attribute just substitute id ...
ERROR: permission denied for sequence cities_id_seq using Postgres
...ce PostgreSQL 8.2 you have to use:
GRANT USAGE, SELECT ON SEQUENCE cities_id_seq TO www;
GRANT USAGE - For sequences, this privilege allows the use of the currval and nextval functions.
Also as pointed out by @epic_fil in the comments you can grant permissions to all the sequences in the schema ...
What's the difference between eval, exec, and compile?
...thing.
eval is for expression and returns value of expression.
expression means "something" while statement means "do something".
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What do querySelectorAll and getElementsBy* methods return?
...etElementsByTagName and querySelectorAll ) work the same as getElementById or do they return an array of elements?
10 A...