Video: Puas yog StringBuilder sai dua txoj hlua sib txuas?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
1) Cov Txoj hlua object yog immutable nyob rau hauv Java tab sis StringBuffer thiab StringBuilder yog cov khoom sib hloov. 2) StringBuffer yog synchronized thaum StringBuilder tsis yog qhov ua StringBuilder sai dua StringBuffer. 3) Concatenation tus neeg teb xov tooj "+" yog siv sab hauv siv StringBuffer lossis StringBuilder.
Ib yam li ntawd ib tug yuav nug, yog txoj hlua hom ntawv sai dua concatenation?
Lub ntsiab yog vim li cas Txoj hlua . hom ntawv () tuaj yeem yooj yim dua hauv zos nrog cov ntawv sau los ntawm cov ntaub ntawv peev txheej whereas kev sib txuas tsis tuaj yeem nyob hauv cheeb tsam yam tsis tau tsim cov kev ua haujlwm tshiab nrog cov lej sib txawv rau txhua hom lus. Cov txiaj ntsig ntawm lub sijhawm yog raws li hauv qab no: Concatenation = 265 millisecond.
Tsis tas li ntawd, thaum twg koj yuav tsum tsis txhob siv StringBuilder? Yog li siv StringBuilder thaum koj xav tau ua ntau kev hloov kho ntawm txoj hlua. Tsis yog tiag koj yuav tsum siv StringBuilder Yog hais tias koj concatenate loj hlua los yog koj muaj ntau concatenations, zoo li nyob rau hauv ib lub voj. Kuv feem ntau siv txoj hlua builder rau ib qho thaiv ntawm cov cai uas yuav ua rau muaj kev sib txuas ntawm peb lossis ntau txoj hlua.
Ib yam li ntawd, uas yog txoj hlua nrawm dua lossis StringBuilder?
Cov khoom ntawm Txoj hlua yog immutable, thiab cov khoom ntawm StringBuffer thiab StringBuilder yog mutable. StringBuffer thiab StringBuilder zoo ib yam, tab sis StringBuilder yog sai dua thiab nyiam dua StringBuffer rau ib txoj haujlwm threaded. Yog xav tau xov kev ruaj ntseg, ces siv StringBuffer.
Thaum twg tus programmer yuav siv txoj hlua vs StringBuilder?
Thaum twg siv koj: if a txoj hlua yog yuav nyob tas mus li thoob plaws hauv qhov kev pab cuam, ces siv String class object vim a Txoj hlua cov khoom yog immutable. Yog ib txoj hlua tau hloov (piv txwv: ntau logic thiab kev ua haujlwm hauv kev tsim kho ntawm lub txoj hlua ) ces siv a StringBuilder yog qhov kev xaiv zoo tshaj plaws.
Pom zoo:
Dab tsi yog qhov sib txawv ntawm kev sib txuas lus taw qhia thiab kev sib txuas tsis raug cai?
Qhov txawv: Kev sib txuas lus taw qhia thiab kev sib txuas tsis muaj kev sib txuas Kev sib txuas lus taw qhia kev sib txuas ua rau muaj kev sib txuas thiab xyuas seb cov lus puas tau txais lossis tsis tau thiab xa rov qab yog tias muaj qhov yuam kev tshwm sim, thaum qhov kev pabcuam tsis sib txuas tsis tau lees tias xa xov
Dab tsi yog qhov txawv ntawm txoj hlua thiab hlua hauv C #?
Qhov sib txawv ntawm txoj hlua thiab hlua hauv C# Hauv C#, hlua yog ib qho alias rau cov hlua hlua hauv. NET moj khaum. Qhov sib txawv me me tsuas yog tias yog tias koj siv cov chav kawm String, koj yuav tsum tau import System namespace rau saum koj cov ntaub ntawv, thaum koj tsis tas yuav ua qhov no thaum siv txoj hlua lo lus tseem ceeb
Dab tsi yog txoj hlua siv los sib piv ob txoj hlua nrog ib leeg hauv C#?
Lub syntax ntawm strcmp() muaj nuj nqi yog: Syntax: int strcmp (const char * str1, const char * str2); strcmp() muaj nuj nqi yog siv los sib piv ob txoj hlua ob txoj hlua str1 thiab str2. Yog tias ob txoj hlua zoo ib yam ces strcmp() rov 0, txwv tsis pub, nws rov qab tus nqi tsis yog xoom
Koj puas tuaj yeem txuas cov hlua txuas ntxiv rau hauv cov hlua hluav taws xob?
Vim hais tias qhov no yog ib qho nyuaj-wired rau hauv cov hluav taws xob qhov hluav taws xob txuas txuas ntxiv tuaj yeem txuas rau nws. Qhov no tsuas yog lub sijhawm nws tuaj yeem txuas txuas txuas ntxiv mus rau hauv lub zog sawb. Extension cords tsuas yog siv rau ib ntus xwb thiab tsis tas yuav tsum tau ntsaws rau hauv phab ntsa qhov hluav taws xob thaum tsis siv
Dab tsi yog qhov sib txawv tseem ceeb ntawm kev sib txuas lus tsis sib xws thiab kev sib txuas lus taw qhia?
1. Hauv kev sib txuas lus tsis muaj kev sib txuas lus tsis tas yuav tsim kev sib txuas ntawm qhov chaw (sender) thiab qhov chaw (receiver). Tab sis nyob rau hauv kev sib txuas-taw qhia kev sib txuas lus kev sib txuas lus yuav tsum tau tsim ua ntej hloov cov ntaub ntawv