Tutorial by Examples: t

When testing you PayPal integration on sandbox, you'll need to have sandbox user accounts set up to use to go through the payment flow. Go to https://developer.paypal.com/developer/accounts/, log in using your PayPal account, and click on "Create Account", as below: Enter in the accoun...

The GlobalFetch interface exposes the fetch function, which can be used to request resources. fetch('/path/to/resource.json') .then(response => { if (!response.ok()) { throw new Error("Request failed!"); } return response.json(...

cat file.txt will print the contents of a file. If the file contains non-ASCII characters, you can display those characters symbolically with cat -v. This can be quite useful for situations where control characters would otherwise be invisible. cat -v unicode.txt Very often, for interactive ...

Use the --number flag to print line numbers before each line. Alternatively, -n does the same thing. $ cat --number file 1 line 1 2 line 2 3 4 line 4 5 line 5 To skip empty lines when counting lines, use the --number-nonblank, or simply -b. $ cat -b file 1 line 1 2 line ...

man <command> This will show the manual page for the specified command. For example, man ping will show: PING(8) BSD System Manager's Manual PING(8) NAME ping -- send ICMP ECHO_REQUEST packets to network hosts SYNOPSIS ping [-AaCDdfno...

$url = "https://api.dropboxapi.com/2/sharing/share_folder" $req = [System.Net.HttpWebRequest]::Create($url) $req.headers["Authorization"] = "Bearer <ACCESS_TOKEN>" $req.Method = "POST" $req.ContentType = "application/json" $enc = [system...

$url = "https://api.dropboxapi.com/2/users/get_current_account" $req = [System.Net.HttpWebRequest]::Create($url) $req.headers["Authorization"] = "Bearer <ACCESS_TOKEN>" $req.Method = "POST" $res = $req.GetResponse() Write-Host "Response Sta...

Static method can be inherited similar to normal methods, however unlike normal methods it is impossible to create "abstract" methods in order to force static method overriding. Writing a method with the same signature as a static method in a super class appears to be a form of overriding,...

int a; printf("%d", a); The variable a is an int with automatic storage duration. The example code above is trying to print the value of an uninitialized variable (a was never initialized). Automatic variables which are not initialized have indeterminate values; accessing these can le...

Consider the below list comprehension: >>> def f(x): ... import time ... time.sleep(.1) # Simulate expensive function ... return x**2 >>> [f(x) for x in range(1000) if f(x) > 10] [16, 25, 36, ...] This results in two calls to f(x) for 1,000 values of...

This code creates a sticky footer. When the content doesn't reach the end of the viewport, the footer sticks to the bottom of the viewport. When the content extends past the bottom of the viewport, the footer is also pushed out of the viewport. View Result HTML: <div class="header"&gt...

To create a new Date object use the Date() constructor: with no arguments Date() creates a Date instance containing the current time (up to milliseconds) and date. with one integer argument Date(m) creates a Date instance containing the time and date corresponding to the Epoch time (...

Defining a new protocol: @protocol NewProtocol - (void)protocolMethod:(id)argument; - (id)anotherMethod; @end

Browse to File > New > Project to bring you up the New Project dialog. Navigate to Visual C# > iOS > iPhone and select Single View App: Give your app a Name and press OK to create your project. Select the Mac Agent icon from the toolbar, as illustrated below: Select the Mac tha...

git ls-remote is one unique command allowing you to query a remote repo without having to clone/fetch it first. It will list refs/heads and refs/tags of said remote repo. You will see sometimes refs/tags/v0.1.6 and refs/tags/v0.1.6^{}: the ^{} to list the dereferenced annotated tag (ie the commit ...

The !important declaration is used to override the usual specificity in a style sheet by giving a higher priority to a rule. Its usage is: property : value !important; #mydiv { font-weight: bold !important; /* This property won't be overridden by the ...

Data Manipulation Language (DML for short) includes operations such as INSERT, UPDATE and DELETE: -- Create a table HelloWorld CREATE TABLE HelloWorld ( Id INT IDENTITY, Description VARCHAR(1000) ) -- DML Operation INSERT, inserting a row into the table INSERT INTO HelloWorld (D...

do './config.pl'; This will read in the contents of the config.pl file and execute it. (See also: perldoc -f do.) N.B.: Avoid do unless golfing or something as there is no error checking. For including library modules, use require or use.

require Exporter; This will ensure that the Exporter module is loaded at runtime if it hasn't already been imported. (See also: perldoc -f require.) N.B.: Most users should use modules rather than require them. Unlike use, require does not call the module's import method and is executed at runti...

When multi-line (?m) modifier is turned off, ^ matches only the input string's beginning: For the regex ^He The following input strings match: Hedgehog\nFirst line\nLast line Help me, please He And the following input strings do not match: First line\nHedgehog\nLast line IHedgehog ...