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Property getters and setters
...g to backup the computed property. Try this:
class Point {
private var _x: Int = 0 // _x -> backingX
var x: Int {
set { _x = 2 * newValue }
get { return _x / 2 }
}
}
Specifically, in the Swift REPL:
15> var pt = Point()
pt: Point = {
_x = 0
}
16> pt.x = 10...
Django admin: how to sort by one of the custom list_display fields that has no database field
How could I sort Customers, depending on number_of_orders they have?
3 Answers
3
...
Email Address Validation in Android on EditText [duplicate]
... target) {
return (!TextUtils.isEmpty(target) && Patterns.EMAIL_ADDRESS.matcher(target).matches());
}
Kotlin:
fun CharSequence?.isValidEmail() = !isNullOrEmpty() && Patterns.EMAIL_ADDRESS.matcher(this).matches()
Edit: It will work On Android 2.2+ onwards !!
Edit: Added miss...
How would you access Object properties from within an object method? [closed]
...
PHP offers a myriad of ways to handle this, including magic methods __get and __set, but I prefer explicit getters and setters. Here's why:
Validation can be placed in setters (and getters for that matter)
Intellisense works with explicit methods
No question whether a property is read only,...
How to open, read, and write from serial port in C?
...;string.h>
#include <termios.h>
#include <unistd.h>
int
set_interface_attribs (int fd, int speed, int parity)
{
struct termios tty;
if (tcgetattr (fd, &tty) != 0)
{
error_message ("error %d from tcgetattr", errno);
return -1...
How to get function parameter names/values dynamically?
...eturn an array of the parameter names of any function passed in.
var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;
var ARGUMENT_NAMES = /([^\s,]+)/g;
function getParamNames(func) {
var fnStr = func.toString().replace(STRIP_COMMENTS, '');
var result = fnStr.slice(fnStr.indexOf('(')+1, fnS...
How to loop through all the properties of a class?
... given by Brannon:
Public Sub DisplayAll(ByVal Someobject As Foo)
Dim _type As Type = Someobject.GetType()
Dim properties() As PropertyInfo = _type.GetProperties() 'line 3
For Each _property As PropertyInfo In properties
Console.WriteLine("Name: " + _property.Name + ", Value: "...
Apply function to all elements of collection through LINQ [duplicate]
...answered May 31 '14 at 4:47
Jack_2060Jack_2060
54311 gold badge77 silver badges1515 bronze badges
...
In Django - Model Inheritance - Does it allow you to override a parent model's attribute?
...rom it:
class AbstractPlace(models.Model):
name = models.CharField(max_length=20)
rating = models.DecimalField()
class Meta:
abstract = True
class Place(AbstractPlace):
pass
class LongNamedRestaurant(AbstractPlace):
name = models.CharField(max_length=255)
food_typ...
Cannot delete or update a parent row: a foreign key constraint fails
...references. This:
ALTER TABLE `advertisers`
ADD CONSTRAINT `advertisers_ibfk_1` FOREIGN KEY (`advertiser_id`)
REFERENCES `jobs` (`advertiser_id`);
...is actually the opposite to what it should be. As it is, it means that you'd have to have a record in the jobs table before the advertis...