Data Types Defined

The type of a variable is decided at runtime by PHP depending on the context in which that variable is used

• Basic types of data in PHP
• String : text or information treated as text (numbers within quotes)
• Integer : whole numbers
• Float : decimal numbers
• Boolean : (or Bool) : True or False
• Compound types:
• Object
• Array
• Special types:
• NULL
• Resources

Important Notes:

• If you want to check out the type and value of certain expression, use var_dump().

• Mention that other languages are strongly typed

• String - text or anything in single or double quotes including numbers or numbers with leading zeros such as 007

• Integer - whole numbers

• Float - decimal numbers

• Bool - True/False, or 0/1

• An array in PHP is actually an ordered map. A map is a type that maps values to keys. this type is optimized in several ways, so you can use it as a real array, or a list (vector), hashtable (which is an implementation of a map), dictionary, collection, stack, queue and probably more. Because you can have another PHP array as a value, you can also quite easily simulate trees.

• A resource is a special variable, holding a reference to an external resource.

• The special NULL value represents that a variable has no value. NULL is the only possible value of type NULL.

• Object - instance of a class