PHP Basics: A Simple Tutorial on PHP

I'm a self-teach PHP developer, and being one, I know how self-teach programmer who likes to have grapple the basics of PHP, need to have a good, yet simple tutorial on the language.

I made this PHP tutorial as simple as possible for you to grapple the basics of the PHP programming language. You can also use this as a good reference of the basics of PHP. So I suggest you bookmark this post and come back here whenever you need. You are most welcome. (^_^)

1. Basic Syntax

A PHP scripting block always starts with <?php and ends with ?>. It can be placed anywhere in the document.

You can also use the shorthand symbol, <? and end with ?>, on servers with shorthand support enabled

However, it is recommended that you use the standard form (<?php) rather than the shorthand form (<?) for maximum compatibility,

Example:

<?php
echo "Hello World";
?>

2. Comments

Use // sign to make a single-line comment or /* and */ signs to make a large comment block.

Example;

<?php
//This is a comment

/*
This is
a comment
block
*/
?>

3. Variables

In php, variables start with a $ sign symbol. Variables may contain strings, numbers, or arrays but should start with a letter.

Rule:
* A variable name must start with a letter or an underscore "_"
* A variable name can only contain alpha-numeric characters and
underscores (a-Z, 0-9, and _ )
* A variable name should not contain spaces. If a variable name should be more
than one word, it should be separated with underscore ($my_string),
or with capitalization ($myString)


Valid: $a, $name, $name1
Invalid: $3, $3name

Example

<?php
$text="Hello World";
echo $text;
?>

4. Operators

Arithmetic Operators

Operator    Description
+           Addition
-           Subtraction
*           Multiplication
/           Division
%           Modulus (division remainder)
++          Increment
--          Decrement

Assignment Operators

Operator    Example     The Same As
=           x=y         x=y
+=          x+=y        x=x+y
-=          x-=y        x=x-y
*=          x*=y        x=x*y
/=          x/=y        x=x/y
%=          x%=y        x=x%y

Comparison Operators

Operator    Description
==          is equal to
!=          is not equal
>           is greater than
<           is less than
>=          is greater than or equal to
<=          is less than or equal to

Logical Operators

Operator    Description
&&          and
||          or
!           not

5. Conditional Statements

if...statement

<?php
$d=date("D");
if ($d=="Fri")
  {
  echo "Have a nice weekend!";
  }
?>

The If...Else Statement

<?php
$d=date("D");
if ($d=="Fri")
  {
  echo "Have a nice weekend!";
  }
else
  {
  echo "Have a nice day!";
  }
?>

The ElseIf Statement

<?php
$d=date("D");
if ($d=="Fri")
  echo "Have a nice weekend!";
elseif ($d=="Sun")
  echo "Have a nice Sunday!";
else
  echo "Have a nice day!";
?>

The Switch Statement

<?php
switch ($x)
{
case 1:
  echo "Number 1";
  break;
case 2:
  echo "Number 2";
  break;
case 3:
  echo "Number 3";
  break;
default:
  echo "No number between 1 and 3";
}
?>

6. Arrays

Indexed Array

$names = array("Babyrose", "Kabalweg");

or

$names[0] = "Babyrose";
$names[1] = "Kabalweg";

Associative Arrays

$age = array("Babyrose"=>27, "Kabalweg"=>28);
$ages["Babyrose"] = "27";
$ages["Kabalweg"] = "28";

Multidimensional Arrays

$families = array
(
  "Badinas"=>array
  (
  "Joel",
  "Kabaleg"
  ),
  "Aranas"=>array
  (
  "Rosalina",
  "Babyrose"
  )
);

7. Looping

while loop

<?php
$x=1;
while($x<=10)
  {
  echo "The number is " . $x . "<br />";
  $x++;
  }
?>

do...while loop

<?php
$x=1;
do
  {
  echo "The number is " . $x . "<br />";
  $x++;
  }
while ($x<10);
?>

for loop

<?php
for ($x=1; $x<=10; $x++)
  {
  echo "The number is " . $x . "<br />";
  }
?>

foreach loop

<?php
$arr=array("one", "two", "three", "four", "five");
foreach ($arr as $value)
  {
  echo "Value: " . $value . "<br />";
  }
?>
</pre>

8. Functions

Simple

<?php
function sayMyName()
  {
  echo "You are Joel Badinas";
  }
?>

Parameterized

<?php
function sayMyName($name)
  {
  echo "You are ".$name;
  }
?>

Returning Values

<?php
function sayMyName()
  {
  $name = "You are Joel Badinas";
  Return $name;
  }
?>