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Data Types in PHP 5

PHP Data types specify the different types of data that are supported in PHP language. There are total 8 data types supported in PHP, which are categorized into 3 main types. They are:

  1. Scalar Types: boolean, integer, float and string.
  2. Compound Types: array and object.
  3. Special Types: resource and NULL.

Let's cover all the different types of data types available in PHP one by one.

PHP Boolean

A boolean data type can have two possible values, either True or False.

$a = true;
$b = false;

NOTE: Here the values true and false are not enclosed within quotes, because these are not strings.

PHP Integer

An Integer data type is used to store any non-decimal numeric value within the range -2,147,483,648 to 2,147,483,647.

An integer value can be negative or positive, but it cannot have a decimal.

$x = -2671;
$y = 7007;

PHP Float

Float data type is used to store any decimal numeric value.

A float(floating point) value can also be either negative or positive.

$a = -2671.01;
$b = 7007.70;

PHP String

String data type in PHP and in general, is a sequence of characters(or anything, it can be numbers and special characters too) enclosed within quotes. You can use single or double quotes.

$str1 = "Hello";
$str2 = "What is your Roll No?";
$str3 = "4";

echo $str1;
echo "<br/>";
echo $str2;
echo "<br/>";
echo "Me: My Roll number is $str3";

Hello What is your Roll No? Me: My Roll number is 4


NULL data type is a special data type which means nothing. It can only have one value, and that is NULL.

If you create any variable and do not assign any value to it, it will automatically have NULL stored in it.

Also, we can use NULL value to empty any variable.

// holds a null value
$b = 7007.70;
// we can also assign null value
$b = null;

PHP Array, Object and Resource Data types

We will study about these data types later on as these are advanced data types and require a better understanding of PHP basics.