Tutorial by Examples: en

In order to begin building with PayPal APIs, you have to create an application to obtain a client ID and secret. Go to https://developer.paypal.com/developer/applications/, sign in, and click on "Create App", as shown below: Next, enter an application name, select the sandbox testing a...

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 ...

This is how to send an SMS text message from a US number using Twilio's Node.js SDK. First you need to install the Node.js client using: npm install twilio Then, you have to create an account on their website. Once you have an account, you'll need the account SID and auth token that you can fi...

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...

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.

The simplest form of macro replacement is to define a manifest constant, as in #define ARRSIZE 100 int array[ARRSIZE]; This defines a function-like macro that multiplies a variable by 10 and stores the new value: #define TIMES10(A) ((A) *= 10) double b = 34; int c = 23; TIMES10(b); //...

func doSomething1(value: Double) { /* ... */ } func doSomething2(value: UInt) { /* ... */ } let x = 42 // x is an Int doSomething1(Double(x)) // convert x to a Double doSomething2(UInt(x)) // convert x to a UInt Integer initializers produce a runtime error if the value ove...

Classes are reference types, meaning that multiple variables can refer to the same instance. class Dog { var name = "" } let firstDog = Dog() firstDog.name = "Fido" let otherDog = firstDog // otherDog points to the same Dog instance otherDog.name = "Rover" // modifying otherDog also...

The Implicit Grant flow is best suited for Web applications. It's easily integrated into a website using JavaScript and doesn't require a server to store the authorization code to retrieve a token. You'll first send the user to the Twitch authorization endpoint. This URL is made up of a the base au...

The second step to creating a subscription for a user is to create and execute a billing agreement, based on an existing activated billing plan. This example assumes that you have already gone through and activated a billing plan in the previous example, and have an ID for that billing plan to refer...

object HelloWorld extends App { println("Hello, world!") } Live demo By extending the App trait, you can avoid defining an explicit main method. The entire body of the HelloWorld object is treated as "the main method". 2.11.0 Delayed Initialization Per the official d...

2.3 The Percent Support Library provides PercentFrameLayout and PercentRelativeLayout, two ViewGroups that provide an easy way to specify View dimensions and margins in terms of a percentage of the overall size. You can use the Percent Support Library by adding the following to your dependencies. ...

HTML comments can be used to leave notes to yourself or other developers about a specific point in code. They can be initiated with <!-- and concluded with -->, like so: <!-- I'm an HTML comment! --> They can be incorporated inline within other content: <h1>This part will be d...

Conditional comments can be used to customize code for different versions of Microsoft Internet Explorer. For example, different HTML classes, script tags, or stylesheets can be provided. Conditional comments are supported in Internet Explorer versions 5 through 9. Older and newer Internet Explorer ...

List Assignment If you are familiar with Perl, C, or Java, you might think that Bash would use commas to separate array elements, however this is not the case; instead, Bash uses spaces: # Array in Perl my @array = (1, 2, 3, 4); # Array in Bash array=(1 2 3 4) Create an array with new ...

Print element at index 0 echo "${array[0]}" 4.3 Print last element using substring expansion syntax echo "${arr[@]: -1 }" 4.3 Print last element using subscript syntax echo "${array[-1]}" Print all elements, each quoted separately echo "${array[@...

An if statement checks whether a Bool condition is true: let num = 10 if num == 10 { // Code inside this block only executes if the condition was true. print("num is 10") } let condition = num == 10 // condition's type is Bool if condition { print("num is 10&...

from collections import Counter c = Counter(["a", "b", "c", "d", "a", "b", "a", "c", "d"]) c # Out: Counter({'a': 3, 'b': 2, 'c': 2, 'd': 2}) c["a"] # Out: 3 c[7] # not in the list (7 oc...

alist = [1, 2, 3, 4, 1, 2, 1, 3, 4] alist.count(1) # Out: 3 atuple = ('bear', 'weasel', 'bear', 'frog') atuple.count('bear') # Out: 2 atuple.count('fox') # Out: 0