為何實(shí)例化對(duì)象的時(shí)候總是既調(diào)用了構(gòu)造函數(shù)又調(diào)用了析構(gòu)函數(shù)?
class?Car?{??? ????function?__construct(){print?'父類(lèi)構(gòu)造函數(shù)被調(diào)用?\n';} ????????????} ???????????? class?Truck?extends?Car{ ????????function?__construct(){print?'子類(lèi)構(gòu)造函數(shù)被調(diào)用';}???????? ????????????????function?__destruct(){print?'析構(gòu)函數(shù)被調(diào)用?\n';?} } $car?=?new?Car(); $truck?=?new?Truck();
2018-10-16
對(duì)象在代碼執(zhí)行完畢之后會(huì)自動(dòng)銷(xiāo)毀,不需要顯示,所以在最后會(huì)調(diào)用析構(gòu)函數(shù)。
2018-05-29
比如說(shuō),你再去定義一個(gè)方法,析構(gòu)函數(shù),會(huì)在你調(diào)用方法之后執(zhí)行。
2018-05-29
內(nèi)置的垃圾清理,因?yàn)榉椒ɑ蛘邔傩灾赶蛟搶?shí)例,被自動(dòng)回收了
2018-05-17
按說(shuō)析構(gòu)函數(shù)不應(yīng)該是對(duì)象注銷(xiāo)時(shí)候才調(diào)用的嗎?