PHP 5 echo and print Statements

PHP Data Types

Variables can store data of different types, and different data types can do different things.

PHP supports the following data types:

  • String
  • Integer
  • Float (floating point numbers - also called double)
  • Boolean
  • Array
  • Object
  • NULL
  • Resource

PHP String

A string is a sequence of characters, like "Hello PHP5!".

A string can be any text inside quotes. You can use single or double quotes:


$x = "Hello PHP5!";
$y = 'Hello PHP5!';

echo $x;
echo "<br>";
echo $y;

PHP Integer

An integer data type is a non-decimal number between -3,154,324,789 and 3,154,324,789.

Rules for integers:

  • An integer must have at least one digit
  • An integer must not have a decimal point
  • An integer can be either positive or negative

In the following example $x is an integer. The PHP var_dump() function returns the data type and value:


$x = 5985;

PHP Float

A floating point number is a number with a decimal point or a number in exponential form.

In the following example $x is a float. The PHP var_dump() function returns the data type and value:


$x = 15.528;

PHP Boolean

A Boolean represents two possible states: TRUE or FALSE.

$x = false;

PHP Array

An array stores multiple values in one single variable.

In the following example $cars is an array. The PHP var_dump() function returns the data type and value:


$cars = array("Volvo","BMW","Toyota");

You will learn a lot more about arrays in later chapters of this tutorial.

PHP Object

An object is a data type which stores data and information on how to process that data.


class Car {
    function Car() {
        $this->model = "VW";

// create an object
$herbie = new Car();

// show object properties
echo $herbie->model;

You will learn more about objects in a later chapter of this tutorial.


Null is a special data type which can have only one value: NULL.

A variable of data type NULL is a variable that has no value assigned to it.

Tip: If a variable is created without a value, it is automatically assigned a value of NULL.

Variables can also be emptied by setting the value to NULL:


$x = "Hello PHP5!";
$x = null;

PHP Resource

The special resource type is not an actual data type. It is the storing of a reference to functions and resources external to PHP.

A common example of using the resource data type is a database call.

We will not talk about the resource type here, since it is an advanced topic.