Tutorial by Examples: i

Here is a basic setting of the Header to change to a new page when a button is clicked. if(isset($_REQUEST['action'])) { switch($_REQUEST['action']) { //Setting the Header based on which button is clicked case 'getState': header("Location: http://NewPageForSta...

Escaping strings is an older (and less secure) method of securing data for insertion into a query. It works by using MySQL's function mysql_real_escape_string() to process and sanitize the data (in other words, PHP is not doing the escaping). The MySQLi API provides direct access to this function $...

Retrieve the last ID generated by an INSERT query on a table with an AUTO_INCREMENT column. Object-oriented Style $id = $conn->insert_id; Procedural Style $id = mysqli_insert_id($conn); Returns zero if there was no previous query on the connection or if the query did not update an AUTO...

Dependency Injection (DI) in the context of using a Dependency Injection Container (DIC) can be seen as a superset of constructor injection. A DIC will typically analyze a class constructor's typehints and resolve its needs, effectively injecting the dependencies needed for the instance execution. ...

To run your unit tests in the simulator using xcodebuild use If you have a workspace (e.g. when using CocoaPods) xcodebuild \ -workspace MyApp.xcworkspace \ -scheme "MyScheme" \ -sdk iphonesimulator \ -destination 'platform=iOS Simulator,name=iPhone 6,OS=9.1' \ test If ...

<script src="example.js"></script> The src attribute works like the href attribute on anchors: you can either specify an absolute or relative URL. The example above links to a file inside the same directory of the HTML document. This is typically added inside the <head&gt...

There are three ways to set the classpath. It can be set using the CLASSPATH environment variable : set CLASSPATH=... # Windows and csh export CLASSPATH=... # Unix ksh/bash It can be set on the command line as follows java -classpath ... javac -classpath ... Note ...

If you want to add all the JARs in directory to the classpath, you can do this concisely using classpath wildcard syntax; for example: someFolder/* This tells the JVM to add all JAR and ZIP files in the someFolder directory to the classpath. This syntax can be used in a -cp argument, a CLASSPA...

Sometimes, just adding all the JARs from a folder isn't enough, for example when you have native code and need to select a subset of JARs. In this case, you need two main() methods. The first one builds a classloader and then uses this classloader to call the second main(). Here is an example which...

Unlike other programming languages, in a batch file a variable is substituted by its actual value before the batch script is run. In other words, the substitution is made when the script is read into memory by the command processor, not when the script is later run. This enables the use of variable...

CSS div { height: 200px; width: 200px; background: url(http://lorempixel.com/200/200/nature/1); mask-image: linear-gradient(to right, white, transparent); } HTML <div></div> In the above example there is an element with an image as its background. The mask that is a...

The content mode property of a view tells how its content should be laid out. In the Interface Builder, the various modes can be selected in the Attributes Inspector. Let's use two image views to see how the various modes work. Scale to Fill The image heights and widths are stretched to mat...

Create a new project It can be just a Single View Application. Add the code Create a new Cocoa Touch Class file (File > New > File... > iOS > Cocoa Touch Class). Name it MyCollectionViewCell. This class will hold the outlets for the views that you add to your cell in the storyboard. ...

Using generics to define the type in instanceof Consider the following generic class Example declared with the formal parameter <T>: class Example<T> { public boolean isTypeAString(String s) { return s instanceof T; // Compilation error, cannot use T as class type here ...

The following might have undefined behavior due to incorrect pointer alignment: char *memory_block = calloc(sizeof(uint32_t) + 1, 1); uint32_t *intptr = (uint32_t*)(memory_block + 1); /* possible undefined behavior */ uint32_t mvalue = *intptr; The undefined behavior happens as the pointer...

The following code has undefined behavior: char buffer[6] = "hello"; char *ptr1 = buffer - 1; /* undefined behavior */ char *ptr2 = buffer + 5; /* OK, pointing to the '\0' inside the array */ char *ptr3 = buffer + 6; /* OK, pointing to just beyond */ char *ptr4 = buffer + 7; /* un...

While there are many different control sequences for io:format and io_lib:format, most of the time you'll use only three different ones: ~s, ~p and ~w. ~s The ~s is for strings. It prints strings, binaries and atoms. (Anything else will cause a badarg error.) It doesn't quote or escape anything...

An extension to PHP called Xdebug is available to assist in profiling PHP applications, as well as runtime debugging. When running the profiler, the output is written to a file in a binary format called "cachegrind". Applications are available on each platform to analyze these files. To...

for /r command can be used to recursively visit all the directories in a directory tree and perform a command. @echo off rem start at the top of the tree to visit and loop though each directory for /r %%a in (.) do ( rem enter the directory pushd %%a echo In directory: cd rem leave...

Go has a built-in logging library known as log with a commonly use method Print and its variants. You can import the library then do some basic printing: package main import "log" func main() { log.Println("Hello, world!") // Prints 'Hello, world!' on a single ...