Tutorial by Examples: s

For checking whether some object is of a certain class, the (binary) instanceof operator can be used since PHP version 5. The first (left) parameter is the object to test. If this variable is not an object, instanceof always returns false. If a constant expression is used, an error is thrown. The ...

An operator can be used to manipulate the flow of objects from Observable to Subscriber. Observable<Integer> integerObservable = Observable.just(1, 2, 3); // creating a simple Integer observable Subscriber<String> mSubscriber = new Subscriber<String>() { @Override publi...

You can use buffers to work with multiple files. When you open a file using :e path/to/file it opens in a new buffer (the command means edit the file). New buffer that holds a temporary copy of the file. You can go to previous buffer with :bp[rev] and next buffer with :bn[ext]. You can go to a...

Commands have one input (STDIN) and two kinds of outputs, standard output (STDOUT) and standard error (STDERR). For example: STDIN root@server~# read Type some text here Standard input is used to provide input to a program. (Here we're using the read builtin to read a line from STDIN.) STDO...

You can use the .Net Math class to do calculations ([System.Math]) If you want to know which methods are available you can use: [System.Math] | Get-Member -Static -MemberType Methods Here are some examples how to use the Math class: PS C:\> [System.Math]::Floor(9.42) 9 PS C:\> [System....

{ echo "contents of home directory" ls ~ } > output.txt

Other examples couldn't clearly explain to me how to trigger the conditional logic. This example also shows that underlying commands will also listen to the -Confirm flag! <# Restart-Win32Computer #> function Restart-Win32Computer { [CmdletBinding(SupportsShouldProcess=$true,Conf...

It is possible to effectively apply a function (cb) which returns a promise to each element of an array, with each element waiting to be processed until the previous element is processed. function promiseForEach(arr, cb) { var i = 0; var nextPromise = function () { if (i >= arr.leng...

Schedulers are an RxJava abstraction about processing unit. A scheduler can be backed by a Executor service, but you can implement your own scheduler implementation. A Scheduler should meet this requirement : Should process undelayed task sequencially (FIFO order) Task can be delayed A Sched...

import pandas as pd df = pd.DataFrame(np.random.randn(5, 5), columns=list('ABCDE')) To generate various summary statistics. For numeric values the number of non-NA/null values (count), the mean (mean), the standard deviation std and values known as the five-number summary : min: minimum (smal...

Supported by IE11+ View Result Use these 3 lines to vertical align practically everything. Just make sure the div/image you apply the code to has a parent with a height. CSS div.vertical { position: relative; top: 50%; transform: translateY(-50%); } HTML <div class="vertica...

Clojure uses prefix notation, that is: The operator comes before its operands. For example, a simple sum of two numbers would be: (+ 1 2) ;; => 3 Macros allow you to manipulate the Clojure language to a certain degree. For example, you could implement a macro that let you write code in infi...

import pylab as plt import numpy as np plt.style.use('ggplot') fig = plt.figure(1) ax = plt.gca() # make some testing data x = np.linspace( 0, np.pi, 1000 ) test_f = lambda x: np.sin(x)*3 + np.cos(2*x) # plot the test data ax.plot( x, test_f(x) , lw = 2) # set the axis labels ax...

The following method computes the sum of integers from 0 to N using recursion. public int sum(final int n) { if (n > 0) { return n + sum(n - 1); } else { return n; } } This method is O(N) and can be reduced to a simple loop using tail-call optimization. In f...

<root xmlns="http://test/"> <element xmlns:example="http://foobar/"> <example:hello_world attribute="another example" /> </element> </root> The expression /root will return nothing, because there is no non-namespaced ...

Any predicate function can be used as a spec. Here's a simple example: (clojure.spec/valid? odd? 1) ;;=> true (clojure.spec/valid? odd? 2) ;;=> false the valid? function will take a spec and a value and return true if the value conforms to the spec and false otherwise. One other inte...

Let's say we have the following function: (defn nat-num-count [nums] (count (remove neg? nums))) We can write a spec for this function by defining a function spec of the same name: (clojure.spec/fdef nat-num-count :args (s/cat :nums (s/coll-of number?)) :ret integer? ...

Meteor has it's own package repository on atmospherejs.com You can add new packages from atmosphere by running: meteor add [package-author-name:package-name] For example: meteor add kadira:flow-router Similarly, you can remove the same package by: meteor remove kadira:flow-router To see...

Hibernate can use two types of fetch when you are mapping the relationship between two entities: EAGER and LAZY. In general, the EAGER fetch type is not a good idea, because it tells JPA to always fetch the data, even when this data is not necessary. Per example, if you have a Person entity and th...

While there are many parameters that can be changed and variations that can be added depending on the desired functionality, this example lays out the basic framework for launching PowerPoint. Note: This code requires that the PowerPoint reference has been added to the active VBA Project. See th...