# 11.2 PHP中的面向对象（二） 在上一节里我们已经看了下如何操作一个对象的方法，这一节主要描述与对象属性有关的东西。有关如何对它进行定义的操作我们已经在上一章中描述过了，这里不再叙述，只讲对其的操作。 ## 读取对象的属性 ````c ZEND_API zval *zend_read_property(zend_class_entry *scope, zval *object, char *name, int name_length, zend_bool silent TSRMLS_DC); ZEND_API zval *zend_read_static_property(zend_class_entry *scope, char *name, int name_length, zend_bool silent TSRMLS_DC); ```` zend_read_property函数用于读取对象的属性，而zend_read_static_property则用于读取静态属性。可以看出，静态属性是直接保存在类上的，与具体的对象无关。 silent参数： <ul> <li>0: 如果属性不存在，则抛出一个notice错误。</li> <li>1: 如果属性不存在，不报错。</li> </ul> 如果所查的属性不存在，那么此函数将返回IS_NULL类型的zval。 ### 更新对象的属性 ````c ZEND_API void zend_update_property(zend_class_entry *scope, zval *object, char *name, int name_length, zval *value TSRMLS_DC); ZEND_API int zend_update_static_property(zend_class_entry *scope, char *name, int name_length, zval *value TSRMLS_DC); ```` zend_update_property用来更新对象的属性，zend_update_static_property用来更新类的静态属性。如果对象或者类中没有相关的属性，函数将自动的添加上。 ### 读写对象与类属性的实例 假设我们已经在扩展中定义好下面的类： ````php class baby { public $age; public static $area; public function __construct($age, $area) { $this->age = $age; self::$area = $area; var_dump($this->age, self::$area); } } ZEND_METHOD(baby, __construct) { zval *age, *area; zend_class_entry *ce; ce = Z_OBJCE_P(getThis()); if( zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "zz", &age, &area) == FAILURE ) { printf("Error\n"); RETURN_NULL(); } zend_update_property(ce, getThis(), "age", sizeof("age")-1, age TSRMLS_CC); zend_update_static_property(ce, "area", sizeof("area")-1, area TSRMLS_CC); age = NULL; area = NULL; age = zend_read_property(ce, getThis(), "age", sizeof("age")-1, 0 TSRMLS_DC); php_var_dump(&age, 1 TSRMLS_CC); area = zend_read_static_property(ce, "area", sizeof("area")-1, 0 TSRMLS_DC); php_var_dump(&area, 1 TSRMLS_CC); } //为类添加age 和 area属性 PHP_MINIT_FUNCTION(say_hello) { zend_class_entry ce; INIT_CLASS_ENTRY(ce,"baby",myclass_method); baby_ce = zend_register_internal_class(&ce TSRMLS_CC); zend_declare_property_null(baby_ce, "age", strlen("age"), ZEND_ACC_PUBLIC TSRMLS_CC); zend_declare_property_null(baby_ce, "area", strlen("area"), ZEND_ACC_STATIC|ZEND_ACC_PUBLIC TSRMLS_CC); return SUCCESS; } ```` <div class="tip-common"> 感谢 [@看你取的破名](http://weibo.com/taokuizu) 发现的错误。 </div> ### 一些其它的快捷函数 #### 更新对象与类的属性 ````c ZEND_API void zend_update_property_null(zend_class_entry *scope, zval *object, char *name, int name_length TSRMLS_DC); ZEND_API void zend_update_property_bool(zend_class_entry *scope, zval *object, char *name, int name_length, long value TSRMLS_DC); ZEND_API void zend_update_property_long(zend_class_entry *scope, zval *object, char *name, int name_length, long value TSRMLS_DC); ZEND_API void zend_update_property_double(zend_class_entry *scope, zval *object, char *name, int name_length, double value TSRMLS_DC); ZEND_API void zend_update_property_string(zend_class_entry *scope, zval *object, char *name, int name_length, const char *value TSRMLS_DC); ZEND_API void zend_update_property_stringl(zend_class_entry *scope, zval *object, char *name, int name_length, const char *value, int value_length TSRMLS_DC); ZEND_API int zend_update_static_property_null(zend_class_entry *scope, char *name, int name_length TSRMLS_DC); ZEND_API int zend_update_static_property_bool(zend_class_entry *scope, char *name, int name_length, long value TSRMLS_DC); ZEND_API int zend_update_static_property_long(zend_class_entry *scope, char *name, int name_length, long value TSRMLS_DC); ZEND_API int zend_update_static_property_double(zend_class_entry *scope, char *name, int name_length, double value TSRMLS_DC); ZEND_API int zend_update_static_property_string(zend_class_entry *scope, char *name, int name_length, const char *value TSRMLS_DC); ZEND_API int zend_update_static_property_stringl(zend_class_entry *scope, char *name, int name_length, const char *value, int value_length TSRMLS_DC); ```` ## links * 11.1 [生成对象的实例](<11.1.md>) * 11.3 [小结](<11.3.md>)