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What is polymorphism, what is it for, and how is it used?
...reach (Vehicle v in vehicles)
{
Console.WriteLine(
string.Format("A {0} has {1} wheels.",
v.GetType().Name, v.Wheels));
}
}
In this example, we create a list of the base class Vehicle, which does not know about how many wheels each of its sub-classes has...
Watermark / hint text / placeholder TextBox
... if (c is ComboBox)
{
return (c as ComboBox).Text == string.Empty;
}
else if (c is TextBoxBase)
{
return (c as TextBox).Text == string.Empty;
}
else if (c is ItemsControl)
{
return (c as ItemsControl).Items...
Is there an interpreter for C? [closed]
... the ISO C90
Standard, but extends C with many
high-level features such as string
type and computational arrays as
first-class objects.
Ch standard is freeware but not open source. Only Ch professional has the plotting capabilities and other features one might want.
I've never looked at this befor...
Disable git EOL Conversions
... Using * text=false does not unset text: it leaves text set to the string value false. This has the same effect as leaving text unspecified (not specifically unset). Using * -text gives it the special unset setting. Unsetting the text attribute on a path tells git not to attempt any end-of-l...
Assign same value to multiple variables at once?
...
actually means $a = ( $b = ( $c = $d ) )
PHP passes primitive types int, string, etc. by value and objects by reference by default.
That means
$c = 1234;
$a = $b = $c;
$c = 5678;
//$a and $b = 1234; $c = 5678;
$c = new Object();
$c->property = 1234;
$a = $b = $c;
$c->property = 5678;
// $...
Initialize parent's protected members with initialization list (C++)
...t along. Something like:
class Parent
{
protected:
Parent( const std::string& something ) : something( something )
{}
std::string something;
}
class Child : public Parent
{
private:
Child() : Parent("Hello, World!")
{
}
}
...
java.lang.IllegalStateException: Cannot (forward | sendRedirect | create session) after response has
...lled in the very same method.
protected void doXxx() {
out.write("some string");
// ...
forward(); // Fail!
}
The response buffer size defaults in most server to 2KB, so if you write more than 2KB to it, then it will be committed and forward() will fail the same way:
java.lang.Illegal...
Are PostgreSQL column names case-sensitive?
...ame" = 'xyz';
Also fix the incorrect double-quotes around 'xyz'. Values (string literals) are enclosed in single quotes.
Read the manual here.
My standing advice is to use legal, lower-case names exclusively so double-quoting is not needed.
...
Convert InputStream to BufferedReader
...ader br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8)); added in Java 7
– brcolow
Mar 19 '15 at 21:51
...
Access denied for user 'root@localhost' (using password:NO)
...ot'.
show databases;
use mysql;
UPDATE mysql.user
SET authentication_string = PASSWORD('MyNewPass'), password_expired = 'N'
WHERE User = 'root' AND Host = 'localhost';
exit;
After that kill the 'mysqld_safe' process and start mysql normally. You should be able to login to mysql using roo...