Tutorial by Examples: n

Lets have the following example.bat and call it with arguments 1 ,2 and 3: @echo off ( shift shift echo %1 ) As the variable expansion will change after the the end brackets context is reached the output will be: 1 As this might be an issue when shifting inside brackets ...

from django.contrib.auth.models import User class UserAdmin(admin.ModelAdmin): list_display = ('email', 'first_name', 'last_name') list_filter = ('is_staff', 'is_superuser') admin.site.unregister(User) admin.site.register(User, UserAdmin) We need to unregister before regis...

First is first, ensure that USE_TZ = True in your settings.py file. Also set a default time zone value to TIME_ZONE such as TIME_ZONE='UTC'. View a complete list of timezones here. If USE_TZ is False, TIME_ZONE will be the time zone that Django will use to store all datetimes. When USE_TZ is enable...

Python's datetime.datetime objects have a tzinfo attribute that is used to store time zone information. When the attribute is set the object is considered Aware, when the attribute is not set it is considered a Naive. To ensure that a timezone is naive or aware, you can use .is_naive() and .is_awar...

I wrote a simple C code foo.c int main() { int i = 0; int j = 0; for (i = 0; i < 5; i++) { j = i + 1; } return 0; } When compiled with -O0 i.e. by disabling all compiler optimizations $ gcc -o foo.S foo.c -O0 -S I got this: .file "foo.c&...

Declaring a DLL procedure to work with different VBA versions: Option Explicit #If Win64 Then Private Declare PtrSafe Sub xLib "Kernel32" Alias "Sleep" (ByVal dwMilliseconds As Long) #ElseIf Win32 Then Private Declare Sub apiSleep Lib "Kernel32" Ali...

Option Explicit #If Win64 Then 'Win64 = True, Win32 = False, Win16 = False Private Declare PtrSafe Sub apiCopyMemory Lib "Kernel32" Alias "RtlMoveMemory" (MyDest As Any, MySource As Any, ByVal MySize As Long) Private Declare PtrSafe Sub apiExitProcess Lib "Kern...

#ElseIf Win32 Then 'Win32 = True, Win16 = False Private Declare Sub apiCopyMemory Lib "Kernel32" Alias "RtlMoveMemory" (MyDest As Any, MySource As Any, ByVal MySize As Long) Private Declare Sub apiExitProcess Lib "Kernel32" Alias "ExitProcess" (ByVa...

val foo : Int by lazy { 1 + 1 } println(foo) The example prints 2.

class MyDelegate { operator fun getValue(owner: Any?, property: KProperty<*>): String { return "Delegated value" } } val foo : String by MyDelegate() println(foo) The example prints Delegated value

This module can be used to : Create a new element. Delete an element from HTML document. Place element in HTML document. Iinitialisation To be able to use the dom-construct module we need to load it as fallow : require(["dojo/dom-construct"], function(domConstruct){...

interface Foo { fun example() } class Bar { fun example() { println("Hello, world!") } } class Baz(b : Bar) : Foo by b Baz(Bar()).example() The example prints Hello, world!

val a = arrayOf(1, 2, 3) // creates an Array<Int> of size 3 containing [1, 2, 3].

val a = Array(3) { i -> i * 2 } // creates an Array<Int> of size 3 containing [0, 2, 4]

val a = arrayOfNulls<Int>(3) // creates an Array<Int?> of [null, null, null] The returned array will always have a nullable type. Arrays of non-nullable items can't be created uninitialized.

General-purpose stopwatch for timing how long a function takes to run: object Benchmark { fun realtime(body: () -> Unit): Duration { val start = Instant.now() try { body() } finally { val end = Instant.now() return Duration.b...

<View style={[(this.props.isTrue) ? styles.bgcolorBlack : styles.bgColorWhite]}> If the value of isTrue is true then it will have black background color otherwise white.

PGSQL> SELECT COALESCE(NULL, NULL, 'HELLO WORLD'); coalesce -------- 'HELLO WORLD'

PGSQL> SELECT COALESCE(NULL, NULL, 'first non null', null, null, 'second non null'); coalesce -------- 'first non null'

PGSQL> SELECT COALESCE(NULL, NULL, NULL); coalesce --------