Show me the code!
This site gathers together all the latest tutorials (coding or otherwise) from the IT Learning Centre at Dundalk Institute of Technology.
Be sure to drop into us if you need help getting any of these working!
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This is how you would display “Hello World” in C++.
#include <iostream>
int main()
{
std::cout << "Hello World!";
}
This is how you would display “Hello World” in C#.
public class HelloWorld
{
public static void Main()
{
System.Console.WriteLine("Hello World!");
}
}
This is how you would display “Hello World” in Visual Basic.
' Allow easy reference to the System namespace classes.
Imports System
' This module houses the application's entry point.
Public Module modmain
' Main is the application's entry point.
Sub Main()
' Write text to the console.
Console.WriteLine ("Hello World using Visual Basic!")
End Sub
End Module
The command line for compiling the program is the following:
vbc.exe /t:exe /debug+ /optionstrict+ /out:.\HelloVB.exe HelloWorld.vb
In the previous line, /out specifies the output file, and /t indicates the target type.
This is how you would display “Hello World” in your Java application.
We break the process of programming in Java into three steps:
So, the code in our file would look like
public class HelloWorld {
public static void main(String[] args) {
// Prints "Hello, World" in the terminal window.
System.out.println("Hello World");
}
}
To compile HelloWorld.java type the text below at the terminal
javac HelloWorld.java
Once you compile your program, you can execute it. This is the exciting part, where the computer follows your instructions. To run the HelloWorld program, type the following in the terminal window:
java HelloWorld
That’s it!
This is how you would display “Hello World” in PowerShell.
Note: PowerShell commands also have the ability to be run in a script with the .ps1 extension but running scripts are disabled by default for security purposes. Firstly, you will need to set the Execution Policy. The cmdlet Get-ExecutionPolicy will show you that the initial policy is set to ‘Restricted’. This will prevent scripts from running. You can change it with the Set-ExecutionPolicy cmdlet. There are four options Restricted, Remote-signed, Signed and Unrestricted. We recommend Remote-Signed as it will allow you to run the scripts that you have created locally and still keep your machine secure.
So, just type
Set-ExecutionPolicy RemoteSigned
Now you can use notepad to create your first script. In Notepad type:
Write-Host "Hello World"
This will need to be saved in a file called something like HelloWorld.ps1.
Then from a PowerShell console type
.\HelloWorld.ps1
The reason you need the .\ is because a PowerShell security feature ensures that you are targeting a specific script in a specific location,. And that’s all there is to it.
This is how you would display “Hello World” in Perl. It’s quite similar to Bash, but note the differences carefully!
Create a text file called hello_world.pl containing the following code:
#!/usr/bin/perl # # The traditional first program. # Strict and warnings are recommended. use strict; use warnings; # Print a message. print "Hello, World!\n";
Navigate to a directory where your hello_world.pl is located and make the file executable:
$ chmod +x hello_world.pl
Now you are ready to execute your first perl script:
./hello_world.pl
This is how you would display “Hello World” in Bash.
Create a text file called hello_world.sh containing the following code:
#!/bin/bash # declare STRING variable STRING="Hello World" #print variable on a screen echo $STRING
Navigate to a directory where your hello_world.sh is located and make the file executable:
$ chmod +x hello_world.sh
Now you are ready to execute your first bash script:
./hello_world.sh
This is how you would display “Hello World” in Ruby.
This is how you would display “Hello World” to the browser in Javascript.
<!DOCTYPE HTML> <html> <body> <p>Header...</p> <script> alert('Hello, World!') </script> <p>...Footer</p> </body> </html>
When listening to developers talk about databases you will usually hear buzz words like robust, scalable, efficient, etc. Discussions will focus on the power of the DBMS (Database Management System) and how it integrates with other technologies. In our case, however, we don’t really care about most of those things. Instead we are going to be looking at the cost of getting started, tools, the user interface and availability of help, especially help for the beginner.
In the following list we’ll talk briefly about each DBMS, give you some pros and cons, and show you how to download and get started with each of them.