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An object is a compound data type. Values of more than one type can be stored together in a single variable. An object is an instance of either a built-in or user defined class. An object is initialized by creating a new statement to instantiate a class.

Multiple objects can be created from a class. Each object has all the properties and methods defined in a class but will have different property values.

Table : Common Functions To Manipulate Objects

Sample Code<?php
$obj = (object)["name" => “John”];
var_dump( isset($obj->name) );
echo $obj->name;
?>

A function is a subprogram that can be called by code externally or internally to the function. It is composed of a sequence of statements called the function body. Values can be passed to a function as parameters or arguments and the function can return a value if applicable.

PHP comes with built-in functions that can be called directly to perform a specific task. It is also possible to create custom functions also called user defined functions.

A function is therefore a block of statements that can be used repeatedly in a program. It will not execute automatically and must be executed by a call to the function.

Table : Common Functions Used To Manipulate Custom Functions

Loops execute one or more statements up to a specific number of times. Loops allow repetitive tasks to be executed using minimal code. Loops allow complex tasks to be simplified by automating similar operations.

Table : Loops

Table : Common Functions Used With Loops

Sample Code<?php
// Display Even Numbers Without Loops
$even_numbers = [2,4,6,8,10];
echo $even_numbers[0]. " ";
echo $even_numbers[1]. " ";
echo $even_numbers[2]. " ";
echo $even_numbers[3]. " ";
echo $even_numbers[4];
?>

An array specifies a variable that can be indexed as a list in rows and columns. The first index is zero as is common in most programming languages.

Table : Common Functions For Manipulating Arrays

Sample Code<?php
$even_numbers = [2,4,6,8,10];
$first_even_number = $even_numbers[0];
$second_even_number = $even_numbers[1];

echo "The first even number is $first_even_number\n";
echo "The second even number is $second_even_number\n";
?>

It is easy to add more items to an array by appending to the end of the list by assigning an index. The 6^th item will have the index 5 because the first index is zero.

Sample Code<?php
$even_numbers = [2,4,6,8,10];
$even_numbers[5] = 12;
?>

PHP logical operators are used to combine conditional statements. Each operand is a conditional that can be evaluated to a true or false value. The value of the conditions determines the overall value of the operator or grouping.

Logical operators are use to control flow of the application. They are normally found as part of a control statement such as if and while.

Table : Logical Operators

Sample Code<?php
$num1 = 5;
$num2 = 10;
if ( $num1 > 0 && $num2 > 0 )
{
	echo “Both AND conditions are true”;
}
else
{
	echo “This condition grouping is false”;
}
if ( $num1 > 0 || $num2 > 0 )
{
	echo “At least one OR condition is true”;
}
else
{
	echo “Both conditions are false”;
}
?>

PHP increment operators are used to increment a variable’s value and decrement operators are used to decrement a variable’s value. PHP also supports pre- and post-increment and decrement operators allowing for the increment or decrement of the value by one.

Table : Increment And Decrement Operators

Sample Code<?php
$num1 = 5;
$num2 = 10;
$num1++; //Post-increment
echo num1;
$num2--; // Post-decrement
echo $num2;
++$num1; //Pre-increment
echo num1;
--$num2; // Pre-decrement
echo $num2;
?>

Comparison operators compare two values which can be numbers of strings.

Table : Comparison Operators

Sample Code<?php
$name1 = "John";
$name2 = "James";
var_dump($name1 == $name2);
var_dump($name1 == 10); 
$num1 = 12;
$num2 = 22;
var_dump($ num1 > $num2);
var_dump($num1 == 10);
?>

Assignment operators are used to define and manipulate scalar variables and not arrays. Scalar variables have the same naming convention where the dollar symbol $ is prepend. Therefore arithmetic types are scalar types. Arrays are aggregate types.

Table : Assignment Operators

Sample Code<?php
$num = 1;
$counter = 1; 
$num += $counter; // Arithmetic Assignment Operator
echo $num;

$greeting = 'Hello ';
$name = 'John';
$greeting .= $name; // Concatenation Assignment Operator
echo $greeting;
?>

The arithmetic operators perform addition, subtraction, multiplication, division, exponentiation, and modulus operations.

Table : Arithmetic Operators

Sample Code<?php
$num1 = 5;
$num2 = 3;
echo ($num1 % $num2)."\n"; // Prints 2
echo ($num1 % $num3)."\n"; // Prints 2
$num1 = -5; // Set To Negative Value
echo ($num1 % $num2)."\n"; // prints -2
$num2 = -3; // Set To Negative Value
echo ($num1 % $num2)."\n"; // prints -2
?>

PHP double quoted strings can format strings using defined variables.

Newline character \n causes a line break when using double quotes.

Concatenation character . and concatenation assignment is .= to combine two strings.

Sample Code<?php
$name = "Jake\nRoberts";
echo "Your name is $name";    // prints Your name is Jake and Roberts on next line
$name .= " Roberts"; // Appends to string via concatenation assignment
echo "My name is" . $name; // Concatenation of string
 ?>

Table : Common Functions For Manipulating Strings