Cov txheej txheem tshawb nrhiav zes yog dab tsi?
Cov txheej txheem tshawb nrhiav zes yog dab tsi?

Video: Cov txheej txheem tshawb nrhiav zes yog dab tsi?

Video: Cov txheej txheem tshawb nrhiav zes yog dab tsi?
Video: Tshuaj theem vim li cas thiaj tau nqi ?/ Siv kho mob dab tsi?/paris polyphylla use for? 2024, Tej zaum
Anonim

Kev Tshawb Fawb : Zes . Zes yog siv cov parentheses () kom paub tseeb tias cov haujlwm Boolean tau ua tiav raws li koj xav tau. Zes synonyms tuaj yeem nthuav koj nrhiav . Piv txwv: Kev haus luam yeeb THIAB (cov tub ntxhais hluas ORteenagers)

Ib yam li ntawd, nws yog nug, dab tsi yog lub ntsiab lus ntawm nesting hais txog cov lus tshawb fawb?

Zes hais txog kev siv cov kab lus sib dhos a nrhiav nqe lus uas siv ntau tshaj ib hom connector lossis tus neeg teb xov tooj (AND, LOSSIS, TSIS). Nest cov ntsiab lus tshawb nrhiav thaum twg tsuas muaj ib lub thawv ntawv nkag. Qauv nestedsearch : "kev xav zoo" THIAB ("kev kawm qib siab" LOSSIS cov tub ntxhais kawm qib siab)

Qhov thib ob, txoj hlua tshawb nrhiav hauv kev tshawb fawb yog dab tsi? A nrhiav txoj hlua yog kev sib txuas ntawm tag nrho cov ntawv, cov lej thiab cov cim nkag los ntawm tus neeg siv rau hauv a nrhiav engine mus nrhiav qhov xav tau. Nrhiav cov hlua yog siv los nrhiav cov ntaub ntawv thiab lawv cov ntsiab lus, cov ntaub ntawv database thiab nplooj ntawv web. A nrhiav txoj hlua tuaj yeem suav nrog cov lus tseem ceeb, cov ntaub ntawv tus lej thiab cov neeg ua haujlwm.

Kuj nug, dab tsi yog cov txheej txheem tshawb nrhiav qib siab?

Cov kev tshawb nrhiav muaj nyob ntawm no (cov lus tseem ceeb, cov neeg ua haujlwm Boolean, kab lus nrhiav ) sib xyaw ua ke los tsim nrhiav nqe lus. Nrhiav cov lus qhia siv thaum nrhiav catalogs, databases, thiab nrhiav cav nrhiav cov phau ntawv, cov khoom, thiab lub vev xaib.

Dab tsi yog 6 tus neeg ua haujlwm Boolean?

Muaj rau logical, lub boolean , cov neeg ua haujlwm . Lawv yog THIAB, conditional THIAB, LOSSIS, conditionalOR, tshwj xeeb LOSSIS, thiab TSIS. ? Txhua qhov kev sib cav rau ib qho laj thawj tus neeg ua haujlwm yuav tsum yog a boolean hom ntaub ntawv, thiab cov txiaj ntsig yeej ib txwm a boolean hom ntaub ntawv.

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