Video: Qhov kev thov PHP yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
PHP $_ Thov yog a PHP super ntiaj teb hloov pauv uas yog siv los sau cov ntaub ntawv tom qab xa daim ntawv HTML. Cov piv txwv hauv qab no qhia tau hais tias ib daim ntawv nrog ib qho kev nkag teb chaws thiab lub pob xa. Thaum tus neeg siv xa cov ntaub ntawv los ntawm txhaj rau "Submit", cov ntaub ntawv xa mus rau cov ntaub ntawv teev nyob rau hauv qhov kev txiav txim ntawm tag.
Khaws qhov no hauv kev txiav txim siab, $ server hauv PHP yog dab tsi?
$_ SERVER yog a PHP super ntiaj teb hloov pauv uas tuav cov ntaub ntawv hais txog headers, paths, thiab tsab ntawv qhov chaw.
Ib sab saum toj, dab tsi yog Superglobals hauv PHP? PHP Ntiaj teb no variables - Superglobals . Ib co predefined variables nyob rau hauv PHP yog " superglobals ", uas txhais tau hais tias lawv ib txwm siv tau, tsis hais txog qhov twg - thiab koj tuaj yeem nkag mus rau lawv los ntawm txhua qhov haujlwm, chav kawm lossis cov ntaub ntawv yam tsis tas yuav ua dab tsi tshwj xeeb.
Ib yam li ntawd, qhov txawv ntawm $ _ POST thiab $ _ thov hauv PHP yog dab tsi?
Re: Qhov txawv ntawm $_POST thiab $_REQUEST GET yog siv rau ib txoj kev nug kev thov - rho tawm cov ntaub ntawv. POST yog siv los hloov cov ntaub ntawv.
$_ server Request_method == ncej yog dab tsi?
$_SERVER [' REQUEST_METHOD '] == ' POST ' txiav txim seb qhov kev thov yog ib qho POST los yog tau txais kev thov. Qhov no tuaj yeem pab txiav txim siab seb puas yuav txheeb xyuas cov khoom nkag los ntawm $_ Tau los yog $_POST . Txawm li cas los xij, koj yog (ISSET( $_POST ["SUBMIT"])) yog txiav txim siab seb puas muaj ib qho ncej variable npe SUBMIT raug xa nrog qhov kev thov.
Pom zoo:
Dab tsi yog qhov sib txawv loj ntawm kev txheeb xyuas qhov yuam kev thiab kev kho cov lej yuam kev?
Ob qhov kev tshawb nrhiav qhov yuam kev thiab kev kho qhov yuam kev yuav tsum muaj qee qhov ntawm cov ntaub ntawv rov qab xa mus nrog cov ntaub ntawv tiag tiag; kev kho yuav tsum muaj ntau tshaj li kev tshawb nrhiav. Parity bits yog ib txoj hauv kev yooj yim rau kev tshawb nrhiav qhov yuam kev. Ib qho parity me ntsis yog ib qho ntxiv me ntsis xa nrog cov ntaub ntawv uas tsuas yog 1-ntsis suav ntawm cov ntaub ntawv
Qhov txawv ntawm qhov kev thov thiab kev thov yog dab tsi?
Raws li lub npe qhov txawv ntawm qhov kev thov andrequests yog qhov kev thov yog ua ntawm (l) whilerequests yog
Dab tsi yog qhov dav thawj qhov kev tshawb nrhiav thiab qhov tob thawj qhov kev tshawb fawb?
BFS sawv rau Breadth First Search. DFS sawv cev rau Kev Tshawb Nrhiav Qhov tob. 2. BFS (Breadth First Search) siv Queue cov qauv ntaub ntawv los nrhiav txoj hauv kev luv tshaj. BFS tuaj yeem siv los nrhiav ib qhov chaw luv tshaj plaws hauv cov duab tsis hnyav, vim tias hauv BFS, peb mus txog qhov kawg uas muaj qhov tsawg kawg nkaus ntawm cov npoo los ntawm qhov chaw vertex
Tus neeg thov kev thov yog dab tsi?
Ib daim ntawv thov tus thov kev pab yog ib daim ntawv thov nyob ib leeg uas khiav ntawm lub tshuab neeg siv khoom thiab tau teeb tsa ua haujlwm raws li J2EE tivthaiv. Tus neeg thov kev thov yog siv los ua cov haujlwm, xws li kev tswj hwm lossis kev tswj hwm
Dab tsi yog qhov txawv ntawm kev thov synchronous thiab asynchronous thov?
Synchronous: Ib qho kev thov synchronous thaiv tus neeg siv khoom kom txog thaum ua haujlwm tiav. Asynchronous Ib qho kev thov asynchronous tsis thaiv tus neeg siv khoom xws li browser teb. Lub sijhawm ntawd, tus neeg siv tuaj yeem ua lwm yam haujlwm. Hauv qhov xwm txheej zoo li no, javascript cav ntawm browser tsis raug thaiv