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Hidden Features of MySQL
...le resource when setting these parameters. For example sort_buffer_size is allocated only if MySQL needs to do a sort. Note: be careful not to run out of memory.
If you have many connects established (i.e. a web site without persistent connections) you might improve performance by setting thread_ca...
Adding a simple UIAlertView
...u want the alert to show, do this:
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"ROFL"
message:@"Dee dee doo doo."
delegate:self
...
Convert UTF-8 encoded NSData to NSString
...ated, you should use -initWithData:encoding:
NSString* newStr = [[NSString alloc] initWithData:theData encoding:NSUTF8StringEncoding];
If the data is null-terminated, you should instead use -stringWithUTF8String: to avoid the extra \0 at the end.
NSString* newStr = [NSString stringWithUTF8String:[t...
Case insensitive 'Contains(string)'
... >= 0? That uses the right culture and is case-insensitive, it doesn't allocate temporary lowercase strings, and it avoids the question of whether converting to lowercase and comparing is always the same as a case-insensitive comparison.
– Quartermeister
Ma...
@synthesize vs @dynamic, what are the differences?
...it
{
if ((self = [super init])) {
data = [[NSMutableDictionary alloc] init];
[data setObject:@"Tom Sawyer" forKey:@"title"];
[data setObject:@"Mark Twain" forKey:@"author"];
}
return self;
}
- (void)dealloc
{
[data release];
[super dealloc];
}
- (NSMetho...
Converting NSString to NSDate (and back again)
...String = @"01-02-2010";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd-MM-yyyy"];
NSDate *dateFromString = [dateFormatter dateFromString:dateString];
NSDate convert to NSString:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[d...
Is there any overhead to declaring a variable within a loop? (C++)
...
Stack space for local variables is usually allocated in function scope. So no stack pointer adjustment happens inside the loop, just assigning 4 to var. Therefore these two snippets have the same overhead.
...
Most efficient way to remove special characters from string
... @SILENT: No, it doesn't, but you should only do that once. If you allocate an array that large each time you call the method (and if you call the method frequently) then the method becomes the slowest by far, and causes a lot of work for the garbage collector.
– Guffa
...
How do I build a numpy array from a generator?
... lists. This is necessary so that space for each item can be consecutively allocated in memory. Consecutive allocation is the key feature of numpy arrays: this combined with native code implementation let operations on them execute much quicker than regular lists.
Keeping this in mind, it is techni...
C: differences between char pointer and array [duplicate]
...sion is actually just a shortcut for array instantiation. So the array is allocated in the stack, and then loaded with the string's data.
– Walt W
Aug 26 '09 at 17:42
...