PHP supports eight data types :

Four scalar types :

1. boolean
2. integer
3. float
4. string

two compund types :

1. array
2. object

and finally two special types :

1. resource
2. null

You can find out a variable or expressions value and type bu using var_dump function, gettype function can also be used for finding out the type of a variable.

If you want to converta variable to a specific data type you can use settype function. Alternatively you can aslo cast it to a different type. You can use following casts to convert a variable to your desired data type in php :

1. (bool), (boolean)
2. (int), (integer)
3. (float) (real), (double)
4. (string)
5. (array)
6. (object)