Data

Data is the foundation of your program. If you define your data the wrong way, your program will run, but will product the wrong results, which can be absolutely frustrating. PHP has an automatic type conversion that can save you work in some situations but increase the difficulty of diagnosing problems. Fortunately, PHP4 contributes an extra level of fuctionality to help you easily test data.

The chapter on Data contains the following sections:
   In Depth
      Data Types
         Variables
         Automatic Creation
         Constants
         Scope
      Working on Data
         Expressions
         Operators
         Control and Structure
         Functions
         Classes and Objects
         Data for Databases
         Data for HTML
      Date and Time
         Julian date
         Time
         Calendar
      Math
         Integer
         Floating-Point Math
         Arbitrary Precision Math
   Immediate Solutions
      Creating Data
         String Data
         Integer and Floating-Point Data
      Testing Data
      Converting Data
      String Functions
      rand(), srand(), and microtime()
      Calculating the date or Time
      Easter

Updates and Additions

Updated and additional sections are in the following list.