About Numbers

When I began discussing variables, I was explicit in stating that PHP has both integer and floating-point (decimal) number types. In my experience, though, these two types can be classified under the generic title numbers without losing any valuable distinction. Valid number-type variables in PHP can be anything like

  • 8

  • 3.14

  • 10980843985

  • -4.2398508

Notice that these values are never quoted—in which case they’d be strings with numeric values—nor do they include commas to indicate thousands. Also, a number is assumed to be positive unless it is preceded by the minus sign (-).

Along with the standard arithmetic operators you can use on numbers (Table 1.1), there are dozens of functions. Two I’ll introduce here are round() and number_format() ...

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