Complex Types

Complex types such as arrays and objects require different treatment. Zend features a single API for these types they're stored using hash tables.

瞰赽 1. MySQL field types

桶跡 2. Available socket types

The types of fields available are

Notes on the use of various SQL types

桶跡 43 1. Resource types for castas

桶跡 43 2. Resource types for castas

The fifth parameter attrsonly should be set to 1 if only attribute types are wanted. If set to 0 both attributes types and attribute values are fetched which is the default behaviour.

蛁 To reduce complexity in the following source examples, we're only working with simple types such as integers at first. A discussion about creating more advanced types follows later in this chapter.

It provides info about columns, such as field names and field types.

Contains this variable's type. For a list of available types, see 桶跡 32 4.

醴翹 Extension Conventions Macros Memory Management Directory and File Functions String Handling Complex Types

A type specifier that says what type the argument data should be treated as. Possible types

Returns the type of the node. All possible types are listed in the table in the introduction.

Scalar variables are those containing an integer, float, string or boolean. Types array, object and resource or not scalar.

Returns name of the node. The name has different meanings for the different types of nodes as illustrated in the following table.

Returns value of the node. The value has different meanings for the different types of nodes as illustrated in the following table.

Adds a zval container to the object. This is useful if you have to add properties which aren't simple types like integers or strings but arrays or other objects.

Hyperwave has its own terminology to name certain pieces of information. This has widely been taken over and extended. Almost all functions operate on one of the following data types.

This function returns the given string converted from one Cyrillic character set to another. The from and to arguments are single characters that represent the source and target Cyrillic character sets. The supported types are

Overload resolution is in general a hard problem given the differences in types between the two languages. The PHP Java extension employs a simple, but fairly effective, metric for determining which overload is the best match.

This function will send the message text to the user nick on the server connected to by connection. IRC servers and other software will not automatically generate replies to NOTICEs in contrast to other message types.

In addition to the basic resource types above, the conversion process can be altered by using the following flags by using the OR operator to combine the resource type with one or more of the following values

Compatability mode with old versions of PHP 3.0. If on, this will cause PHP to automatically assign types to results according to their Sybase type, instead of treating them all as strings. This compatability mode will probably not stay around forever, so try applying whatever necessary changes to your code, and turn it off.

Beginning with PHP 4.3, bits and channels are present for other image types, too. However, the presence of these values can be a bit confusing. As an example, GIF always uses 3 channels per pixel, but the number of bits per pixel cannot be calculated for an animated GIF with a global color table.

In the tradition of PHP, arrays and hashtables may pretty much be used interchangably. Note that hashtables in PHP may only be indexed by integers or strings and that arrays of primitive types in Java can not be sparse. Also note that these constructs are passed by value, so may be expensive in terms of memory and time.

Forces conversion to an object. Objects remain untouched. NULL values are converted to an empty object. Arrays are converted to objects by introducing their keys as properties into the objects and their values as corresponding property contents in the object. All other types result in an object with the property scalar, having the corresponding source value as content.

蛁 It is currently impossible to register resource variables in a session. For example, you cannot create a connection to a database and store the connection id as a session variable and expect the connection to still be valid the next time the session is restored. PHP functions that return a resource are identified by having a return type of resource in their function definition. A list of functions that return resources are available in the resource types appendix.