Tutorial by Examples: ar

This variable is used to set output record separator, by default a newline. awk 'BEGIN{ORS=","} {print $0}' file

let let num=1+2 let num="1+2" let 'num= 1 + 2' let num=1 num+=2 You need quotes if there are spaces or globbing characters. So those will get error: let num = 1 + 2 #wrong let 'num = 1 + 2' #right let a[1] = 1 + 1 #wrong let 'a[1] = 1 + 1' ...

#!/bin/bash echo $(( 1 + 2 )) Output: 3 # Using variables #!/bin/bash var1=4 var2=5 ((output=$var1 * $var2)) printf "%d\n" "$output" Output: 20

#!/bin/bash expr 1 + 2 Output: 3

Whitespace matters when assigning variables. foo = 'bar' # incorrect foo= 'bar' # incorrect foo='bar' # correct The first two will result in syntax errors (or worse, executing an incorrect command). The last example will correctly set the variable $foo to the text "bar".

Every single ViewGroup (e.g. LinearLayout, RelativeLayout, CoordinatorLayout, etc.) needs to store information about its children's properties. About the way its children are being laid out in the ViewGroup. This information is stored in objects of a wrapper class ViewGroup.LayoutParams. To include...

Press controlr and type a pattern. For example, if you recently executed man 5 crontab, you can find it quickly by starting to type "crontab". The prompt will change like this: (reverse-i-search)`cr': man 5 crontab The `cr' there is the string I typed so far. This is an incremental s...

Due to not being Excel-VBA exclusive contents this Example has been moved to VBA documentation. Link: Dynamic Arrays (Array Resizing and Dynamic Handling)

Configure your app's URLconf to automatically use a URL namespace by setting the app_name attribute: # In <myapp>/urls.py from django.conf.urls import url from .views import overview app_name = 'myapp' urlpatterns = [ url(r'^$', overview, name='overview'), ] This will set t...

You can create temporary files which has a visible name on the file system which can be accessed via the name property. The file can, on unix systems, be configured to delete on closure (set by delete param, default is True) or can be reopened later. The following will create and open a named temp...

As we know we can declare an array with default values: int[] arr = new int[10]; This will create an array of 10 integers with each element of the array having value 0 (the default value of type int). To create an array initialized with a non-default value, we can use Enumerable.Repeat from the...

<svg width="900px" height="400px" viewBox="900 400"> <defs> <filter id="GaussianHardEdge" x="0%" y="0%" width="100%" height="100%"> <feGaussianBlur stdDeviation="5"/&gt...

Partial classes provide an ability to split class declaration (usually into separate files). A common problem that can be solved with partial classes is allowing users to modify auto-generated code without fearing that their changes will be overwritten if the code is regenerated. Also multiple devel...

array_reduce reduces array into a single value. Basically, The array_reduce will go through every item with the result from last iteration and produce new value to the next iteration. Usage: array_reduce ($array, function($carry, $item){...}, $defaul_value_of_first_carry) $carry is the result f...

open(my $fh, '<', "/some/path") or die $!; my @ary = <$fh>; When evaluated in list context, the diamond operator returns a list consisting of all the lines in the file (in this case, assigning the result to an array supplies list context). The line terminator is retained, and ...

Characters can be escaped using character references, in element content or attribute values. Their Unicode codepoint can be specified in decimal or hex. <?xml version="1.0"?> <document> The line feed character can be escaped with a decimal (
) or hex (
) ...

This is a specialized field, used to store binary data. It only accepts bytes. Data is base64 serialized upon storage. As this is storing binary data, this field cannot be used in a filter. from django.db import models class MyModel(models.Model): my_binary_data = models.BinaryField() ...

For...Next Using the iterator variable as the index number is the fastest way to iterate the elements of an array: Dim items As Variant items = Array(0, 1, 2, 3) Dim index As Integer For index = LBound(items) To UBound(items) 'assumes value can be implicitly converted to a String: D...

Partial method consists of the definition in one partial class declaration (as a common scenario - in the auto-generated one) and the implementation in another partial class declaration. using System; namespace PartialClassAndMethods { public partial class PartialClass // Auto-generated ...

Objective c: //this is the dictionary you start with. NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"name1", @"Sam",@"name2", @"Sanju",nil]; //check if the dictionary contains the key you are going to modify. In this example, @&qu...