Tutorial by Examples: an

When using inheritance, you can specify the virtual keyword: struct A{}; struct B: public virtual A{}; When class B has virtual base A it means that A will reside in most derived class of inheritance tree, and thus that most derived class is also responsible for initializing that virtual base: ...

Aside from single inheritance: class A {}; class B : public A {}; You can also have multiple inheritance: class A {}; class B {}; class C : public A, public B {}; C will now have inherit from A and B at the same time. Note: this can lead to ambiguity if the same names are used in multipl...

Assuming the page includes an HTML element like: <p class="small-paragraph"> This is a small <a href="https://en.wikipedia.org/wiki/Paragraph">paragraph</a> with a <a class="trusted" href="http://stackexchange.com">link</a>...

If you don't want to add Unix commands to your PATH on Windows, you can download a standalone SSH client like PuTTY. Download PuTTY here, then follow the instructions below to get a build machine. Call meteor admin get-machine <os-architecture> --json Copy and save the private key from the...

Bold Text To bold text, use the <strong> or <b> tags: <strong>Bold Text Here</strong> or <b>Bold Text Here</b> What’s the difference? Semantics. <strong> is used to indicate that the text is fundamentally or semantically important to the surrounding...

To offset text either upward or downward you can use the tags <sup> and <sub>. To create superscript: <sup>superscript here</sup> To create subscript: <sub>subscript here</sub>

If you are using the PASSWORD_DEFAULT method to let the system choose the best algorithm to hash your passwords with, as the default increases in strength you may wish to rehash old passwords as users log in <?php // first determine if a supplied password is valid if (password_verify($plaintex...

Local variables are defined within a function, method, or closure: func printSomething() { let localString = "I'm local!" print(localString) } func printSomethingAgain() { print(localString) // error } Global variables are defined outside of a function, method, or c...

Mathematical operations on values other than numbers return NaN. "a" + 1 "b" * 3 "cde" - "e" [1, 2, 3] * 2 An exception: Single-number arrays. [2] * [3] // Returns 6 Also, remember that the + operator concatenates strings. "a" + "b&...

Generally, Math functions that are given non-numeric arguments will return NaN. Math.floor("a") The square root of a negative number returns NaN, because Math.sqrt does not support imaginary or complex numbers. Math.sqrt(-1)

window.isNaN() The global function isNaN() can be used to check if a certain value or expression evaluates to NaN. This function (in short) first checks if the value is a number, if not tries to convert it (*), and then checks if the resulting value is NaN. For this reason, this testing method may ...

Output buffering allows you to store any textual content (Text, HTML) in a variable and send to the browser as one piece at the end of your script. By default, php sends your content as it interprets it. <?php // Turn on output buffering ob_start(); // Print some output to the buffer (via...

ob_start(); $user_count = 0; foreach( $users as $user ) { if( $user['access'] != 7 ) { continue; } ?> <li class="users user-<?php echo $user['id']; ?>"> <a href="<?php echo $user['link']; ?>"> <?php echo $user...

A block that performs addition of two double precision numbers, assigned to variable addition: double (^addition)(double, double) = ^double(double first, double second){ return first + second; }; The block can be subsequently called like so: double result = addition(1.0, 2.0); // result =...

A module can be "imported", or otherwise "required" by the require() function. For example, to load the http module that ships with Node.js, the following can be used: const http = require('http'); Aside from modules that are shipped with the runtime, you can also require mod...

Considering the following users table: idusername1User12User23User34User45User5 In order to constrain the number of rows in the result set of a SELECT query, the LIMIT clause can be used together with one or two positive integers as arguments (zero included). LIMIT clause with one argument When ...

On StackExchange sites, code snippets may provide optional syntax highlighting. On sites like Stack Overflow the default language is derived from the tags used in the associated question (if applicable). In addition, a code snippet's syntax highlighting language may also be defined by adding an HTML...

One use case for assertion is precondition and postcondition. This can be very useful to maintain invariant and design by contract. For a example a length is always zero or positive so this function must return a zero or positive value. #include <stdio.h> /* Uncomment to disable `assert()`...

When an exception object is created (i.e. when you new it), the Throwable constructor captures information about the context in which the exception was created. Later on, this information can be output in the form of a stacktrace, which can be used to help diagnose the problem that caused the excep...

To see the log with changes inline, use the -p or --patch options. git log --patch Example (from Trello Scientist repository) ommit 8ea1452aca481a837d9504f1b2c77ad013367d25 Author: Raymond Chou <[email protected]> Date: Wed Mar 2 10:35:25 2016 -0800 fix readme error link diff ...