Tutorial by Examples: le
set var=10
set /a var=%var%+10
echo %var%
The final value of var is 20.
The second line is not working within a command block used for example on an IF condition or on a FOR loop as delayed expansion would be needed instead of standard environment variable expansion.
Here is another, better w...
FOREIGN KEY constraint can be added on existing tables that are still not in relationship. Imagine that we have Company and Employee tables where Employee table CompanyId column but don't have foreign key relationship.
ALTER TABLE statement enables you to add foreign key constraint on an existing c...
FOREIGN KEY columns with constraint can be added on existing tables that are still not in relationship. Imagine that we have Company and Employee tables where Employee table don't have CompanyId column.
ALTER TABLE statement enables you to add new column with foreign key constraint that references ...
Create a set
local set = {} -- empty set
Create a set with elements by setting their value to true:
local set = {pear=true, plum=true}
-- or initialize by adding the value of a variable:
local fruit = 'orange'
local other_set = {[fruit] = true} -- adds 'orange'
Add a member to the ...
Swift
let bundleIdentifier = NSBundle.mainBundle().bundleIdentifier()
NSUserDefaults.standardUserDefaults().removePersistentDomainForName(bundleIdentifier)
Objective-C
NSString *bundleIdentifier = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersi...
This is a basic Hello World program in NASM assembly for 32-bit x86 Linux, using system calls directly (without any libc function calls). It's a lot to take in, but over time it will become understandable. Lines starting with a semicolon(;) are comments.
If you don't already know low-level Unix sy...
git clean -i
Will print out items to be removed and ask for a confirmation via commands like the follow:
Would remove the following items:
folder/file1.py
folder/file2.py
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each
5: quit...
>>> import os
>>> os.stat(path_to_file).st_size == 0
or
>>> import os
>>> os.path.getsize(path_to_file) > 0
However, both will throw an exception if the file does not exist. To avoid having to catch such an error, do this:
import os
def is_empty_...
Rather than use clearRect which makes all pixels transparent you may want a background.
To clear with a gradient
// create the background gradient once
var bgGrad = ctx.createLinearGradient(0,0,0,canvas.height);
bgGrad.addColorStop(0,"#0FF");
bgGrad.addColorStop(1,"#08F");
...
Given the 4 points of a cubic Bezier curve the following function returns its length.
Method: The length of a cubic Bezier curve does not have a direct mathematical calculation. This "brute force" method finds a sampling of points along the curve and calculates the total distance spanne...
When writing wrappers for unmanaged resources, you should subclass SafeHandle rather than trying to implement IDisposable and a finalizer yourself. Your SafeHandle subclass should be as small and simple as possible to minimize the chance of a handle leak. This likely means that your SafeHandle imple...
A type qualifier; when applied to a type, produces the volatile-qualified version of the type. Volatile qualification plays the same role as const qualification in the type system, but volatile does not prevent objects from being modified; instead, it forces the compiler to treat all accesses to suc...
MSTest (the default testing framework) requires you to have your test classes decorated by a [TestClass] attribute, and the test methods with a [TestMethod] attribute, and to be public.
[TestClass]
public class FizzBuzzFixture
{
[TestMethod]
public void Test1()
{
//arrange...
string[] portNames = SerialPort.GetPortNames();
Enable and upgrade setup
php bin/magento module:enable YKM_Custom
php bin/magento setup:upgrade
Disable the Module
php bin/magento module:disable YKM_Custom
Another One - module uninstall script is executed and whole module gets deleted afterwards. Only modules installed through Composer ca...
When we use @SpringApplicationConfiguration it will use configuration from application.yml [properties] which in certain situation is not appropriate. So to override the properties we can use @TestPropertySource annotation.
@TestPropertySource(
properties = {
"spring...
