Data types in PHP

This tutorial explains the range of data types that can be used in PHP including:

  • String (letters, numbers and other characters – stored inside quotation marks)
  • Integer (whole positive or negative numbers)
  • Float (positive or negative real numbers – numbers with decimal place)
  • Boolean (can be only one of two possible values – either true or false)
  • NULL (no value / nothing)

String values are always stored inside quotation marks (can be double or single quotation marks, but they must match) eg. $mySentence = “Hello world”;

Integer, float and boolean values are not contained inside quotation marks eg. myNumber = 5;

It is important to note that when working with numbers, if you intend to treat a value as a number (and it will be used for numeric comparisons and calculations) such as a score in a game, then it should be in the form of an integer or float and not stored inside quotation marks. However, if a number value is not going to be used for calculations eg. a phone number or ZIP code, then it can be stored as a string value inside quotation marks.

Watch the video below and scroll down to see the sample code.

PHP sample code:

 $name = "Batman"; // strings (letters, numbers and other characters)
 $age = 25; // integers (whole positive or negative numbers - no decimal places)
 $num = 30.256; // floats (positive or negative real numbers - can have decimal place)
 $myboolean = true; // Boolean (only one of two possible values - true or false)
 $myvariable = NULL; // NULL (no value / nothing)

PHP Manual references: