静态属性有两种，局部静态跟全局静态，局部静态是只在函数作用域内有用，外部引用时会报错，全局静态则在函数内外部都可以引用且改变值。静态属性只会初始化一次，然后就会存在一块固定的内存块里。function test(){ static $var = 5; //static $var = 1+1;就会报错 $var++; echo $var . ' ';}test(); //2test(); //3test(); //4echo $var; //报错：Notice: Undefined variable: varfunction static_global(){ global $glo; $glo++; echo $glo.'<br>';}static_global(); //1static_global(); //2static_global(); //3echo $glo . '<br>'; //3关于静态方法与非静态方法之间调用的注意事项，下面举例说明：class Banji{ public static $nums = 0; public $name = ''; public function __construct($name){ $this->name = $name; self::$nums++; } public function nums(){ echo self::$nums; echo '<br>'; echo $this->name; echo '<br>'; } public static function test(){ echo self::$nums; echo '<br>'; } public static function test1(){ echo self::$nums; echo '<br>'; echo $this->name; echo '<br>'; } public static function test2(){ self::nums(); } public static function test3(){ $this->nums(); } public function test4(){ self::test(); }}$student = new Banji('Susunma');$student->nums(); //1 Susunma$student = new Banji('Susunma1');$student->nums(); //2 Susunma1$student = new Banji('Susunma2');$student->nums(); //3 Susunma2$student->test(); //3$student->test1(); //Fatal error: Uncaught Error: Using $this when not in object context 即静态方法中不能调用非静态属性Banji::test(); //3Banji::test1(); //Fatal error: Uncaught Error: Using $this when not in object context$student->test2(); //DePRecated: Non-static method Banji::nums() should not be called statically 非静态方法中不能以静态方式调用$student->test3(); //Fatal error: Uncaught Error: Using $this when not in object context 即静态方法中不能调用非静态方法$student->test4(); //3 即非静态方法可以访问静态方法以及静态属性
