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How do you trigger a block after a delay, like -performSelector:withObject:afterDelay:?
... using performSelector:withObject:afterDelay: but with an argument like int / double / float ?
19 Answers
...
Swift variable decorations with “?” (question mark) and “!” (exclamation mark)
...u don't check for nil you'll get a runtime error)
// Cannot be nil
var x: Int = 1
// The type here is not "Int", it's "Optional Int"
var y: Int? = 2
// The type here is "Implicitly Unwrapped Optional Int"
var z: Int! = 3
Usage:
// you can add x and z
x + z == 4
// ...but not x and y, because ...
How to map a composite key with JPA and Hibernate?
...inner class):
public class TimePK implements Serializable {
protected Integer levelStation;
protected Integer confPathID;
public TimePK() {}
public TimePK(Integer levelStation, Integer confPathID) {
this.levelStation = levelStation;
this.confPathID = confPathID;
...
Are there any SHA-256 javascript implementations that are generally considered trustworthy?
...nst hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer);
// convert ArrayBuffer to Array
const hashArray = Array.from(new Uint8Array(hashBuffer));
// convert bytes to hex string
const hashHex = hashArray.map(b => ('00' + b.toString(16)).slice(-2)).joi...
Objective-C: Property / instance variable in category
...
.h-file
@interface NSObject (LaserUnicorn)
@property (nonatomic, strong) LaserUnicorn *laserUnicorn;
@end
.m-file
#import <objc/runtime.h>
static void * LaserUnicornPropertyKey = &LaserUnicornPropertyKey;
@implementat...
Constructors in Go
... have a struct like this :
type Thing struct {
Name string
Num int
}
then, if the zero values aren't fitting, you would typically construct an instance with a NewThing function returning a pointer :
func NewThing(someParameter string) *Thing {
p := new(Thing)
p.Name = somePara...
How do you create a Swift Date object?
... Time in Swift
In Swift, dates and times are stored in a 64-bit floating point number measuring the number of seconds since the reference date of January 1, 2001 at 00:00:00 UTC. This is expressed in the Date structure. The following would give you the current date and time:
let currentDateTime = Da...
How to change the default collation of a table?
...set and collation of a table including those of existing columns (note the convert to clause):
alter table <some_table> convert to character set utf8mb4 collate utf8mb4_unicode_ci;
Edited the answer, thanks to the prompting of some comments:
Should avoid recommending utf8. It's almost n...
PHP Timestamp into DateTime
Do you know how I can convert this to a strtotime, or a similar type of value to pass into the DateTime object?
4 Answer...
How to render a PDF file in Android
...rer(getSeekableFileDescriptor());
// let us just render all pages
final int pageCount = renderer.getPageCount();
for (int i = 0; i < pageCount; i++) {
Page page = renderer.openPage(i);
// say we render for showing on the screen
page.render(mBitmap, null, null, Page.RENDER_MODE...