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Why rename synthesized properties in iOS with leading underscores? [duplicate]
...s is an artifact of a previous version of the Objective-C runtime.
Originally, @synthesize was used to create accessors methods, but the runtime still required that instance variables had to be instantiated explicitly:
@interface Foo : Bar {
Baz *_qux;
}
@property (retain) Baz *qux;
@end
@imp...
Programmatically find the number of cores on a machine
...ne, if a system is capable of turning some off they might not be counted. Calling sysconf with "_SC_NPROCESSORS_CONF" will return the total CPUs configured.
– Chris S
Apr 23 '11 at 18:43
...
Convert Rows to columns using 'Pivot' in SQL Server
...n but it is easier to see the correct code using a hard-coded version initially.
First up, here are some quick table definitions and data for use:
CREATE TABLE #yt
(
[Store] int,
[Week] int,
[xCount] int
);
INSERT INTO #yt
(
[Store],
[Week], [xCount]
)
VALUES
(102, 1, 96),
(...
Get nth character of a string in Swift programming language
...ng a linear loop inside another linear loop means this for loop is accidentally O(n2) — as the length of the string increases, the time this loop takes increases quadratically. Instead of doing that you could use the characters's string collection.
– ignaciohugog
...
Redirecting Output from within Batch file
... good and fast way that only opens and positions the file once
@echo off
call :sub >output.txt
exit /b
:sub
command1
command2
...
commandN
Edit 2020-04-17
Every now and then you may want to repeatedly write to two or more files. You might also want different messages on the screen. It is sti...
How to paste over without overwriting register
Does anyone know of a way to paste over a visually selected area without having the selection placed in the default register?
...
How to get an object's properties in JavaScript / jQuery?
...Script's native for in loop:
var obj = {
foo: 'bar',
base: 'ball'
};
for(var key in obj) {
alert('key: ' + key + '\n' + 'value: ' + obj[key]);
}
or using jQuery's .each() method:
$.each(obj, function(key, element) {
alert('key: ' + key + '\n' + 'value: ' + element);
});
W...
Python Process Pool non-daemonic?
...to create a python Pool that is non-daemonic? I want a pool to be able to call a function that has another pool inside.
8 A...
How to remove constraints from my MySQL table?
...
Postgres, MSSQL, and Oracle all have alter table .. drop constraint. MySQL is the odd one out, it seems.
– Jared Beck
Mar 23 '15 at 23:48
...
What does Python's eval() do?
...less until you find a need for it. It is used on sites like codepad.org to allow you to execute scripts in a test environment. eval() can also be used to execute highly-dynamic code, but you should make yourself fully aware of the security and performance risks before using it.
...