Tutorial by Examples: me

Sometimes it's useful to test private & protected methods as well as public ones. class Car { /** * @param mixed $argument * * @return mixed */ protected function drive($argument) { return $argument; } /** * @return bool *...

You can add hours, minutes, seconds and nanoseconds: LocalTime time = LocalTime.now(); LocalTime addHours = time.plusHours(5); // Add 5 hours LocaLTime addMinutes = time.plusMinutes(15) // Add 15 minutes LocalTime addSeconds = time.plusSeconds(30) // Add 30 seconds LocalTime addNanoseconds = ti...

If two pointers are compared using <, >, <=, or >=, the result is unspecified in the following cases: The pointers point into different arrays. (A non-array object is considered an array of size 1.) int x; int y; const bool b1 = &x < &y; // unspecified int ...

If a function has multiple arguments, it is unspecified what order they are evaluated in. The following code could print x = 1, y = 2 or x = 2, y = 1 but it is unspecified which. int f(int x, int y) { printf("x = %d, y = %d\n", x, y); } int get_val() { static int x = 0; r...

These attributes are used when the layout is rendered in Android Studio, but have no impact on the runtime. In general you can use any Android framework attribute, just using the tools: namespace rather than the android: namespace for layout preview. You can add both the android: namespace attribu...

As of Kafka 0.9, the new high level KafkaConsumer client is availalbe. It exploits a new built-in Kafka protocol that allows to combine multiple consumers in a so-called Consumer Group. A Consumer Group can be describes as a single logical consumer that subscribes to a set of topics. The partions ov...

KafkaConsumers request messages from a Kafka broker via a call to poll() and their progress is tracked via offsets. Each message within each partition of each topic, has a so-called offset assigned—its logical sequence number within the partition. A KafkaConsumer tracks its current offset for each p...

This topic explains the concept of an object reference; it is targeted at people who are new to programming in Java. You should already be familiar with some terms and meanings: class definition, main method, object instance, and the calling of methods "on" an object, and passing parameter...

Every custom loader must directly or indirectly extend the java.lang.ClassLoader class. The main extension points are the following methods: findClass(String) - overload this method if your classloader follows the standard delegation model for class loading. loadClass(String, boolean) - overloa...

A statement is constructed with a function such as sqlite3_prepare_v2(). A prepared statement object must be cleaned up with sqlite3_finalize(). Do not forget this in case of an error. If parameters are used, set their values with the sqlite3_bind_xxx() functions. The actual execution happens whe...

An enumerations value in no way needs to be unique: #include <stdlib.h> /* for EXIT_SUCCESS */ #include <stdio.h> /* for printf() */ enum Dupes { Base, /* Takes 0 */ One, /* Takes Base + 1 */ Two, /* Takes One + 1 */ Negative = -1, AnotherZero /* Takes Negativ...

ORDER BY FIND_IN_SET(card_type, "MASTER-CARD,VISA,DISCOVER") -- sort 'MASTER-CARD' first. ORDER BY x IS NULL, x -- order by `x`, but put `NULLs` last. Custom ordering SELECT * FROM some_table WHERE id IN (118, 17, 113, 23, 72) ORDER BY FIELD(id, 118, 17, 113, 23, 72); Returns th...

Memcache is a distributed object caching system and uses key-value for storing small data. Before you start calling Memcache code into PHP, you need to make sure that it is installed. That can be done using class_exists method in php. Once it is validated that the module is installed, you start with...

A simple example which provides the options: OptAlt. OptDetails-h--helpShow help-v--versionShow version info-dr path--doc-root pathAn option which takes a secondary parameter (a path)-i--installA boolean option (true/false)-*--Invalid option #!/bin/bash dr='' install=false skip=false for op ...

Class Car ... ' Parameterless Constructor Public Sub Class_Initialize() distances_ = Array(0) End Sub ' Default initialization method that can be invoked without ' explicitly using the method name. Public Default Function Init(wheels) wheels_ = ...

SET TEST=0 IF %TEST% == 0 ( echo TEST FAILED ) ELSE IF %TEST% == 1 ( echo TEST PASSED ) ELSE ( echo TEST INVALID )

Enumeration types can also be declared without giving them a name: enum { buffersize = 256, }; static unsigned char buffer [buffersize] = { 0 }; This enables us to define compile time constants of type int that can as in this example be used as array length.

Julia uses the standard mathematical meanings of arithmetic operations when applied to matrices. Sometimes, elementwise operations are desired instead. These are marked with a full stop (.) preceding the operator to be done elementwise. (Note that elementwise operations are often not as efficient as...

You can have functions in the PS1 variable, just make sure to single quote it or use escape for special chars: gitPS1(){ gitps1=$(git branch 2>/dev/null | grep '*') gitps1="${gitps1:+ (${gitps1/#\* /})}" echo "$gitps1" } PS1='\u@\h:\w$(gitPS1)$ ' It will...

timeNow(){ echo "$(date +%r)" } PS1='[$(timeNow)] \u@\h:\w$ ' It will give you a prompt like this: [05:34:37 PM] user@Host:/path$ Notes: Make the changes in ~/.bashrc or /etc/bashrc or ~/.bash_profile or ~./profile file (depending on the OS) and save it. Run source ~/.ba...