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Koj ntxiv ntau yam khoom rau ArrayList hauv Java li cas?
Koj ntxiv ntau yam khoom rau ArrayList hauv Java li cas?

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Video: Koj ntxiv ntau yam khoom rau ArrayList hauv Java li cas?
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Ntxiv ntau yam khoom rau ArrayList hauv Java

  1. Ntxiv ntau yam khoom rau arraylist – ArrayList . addAll() rau ntxiv tag nrho cov khoom los ntawm lwm phau ntawv mus rau arraylist , siv ArrayList .
  2. Ntxiv tsuas xaiv cov khoom rau arraylist . Txoj kev no siv Java 8 kwj API.

Ib yam li ntawd, tib neeg nug, ua li cas koj ntxiv ntau lub ntsiab lus rau ArrayList hauv Java?

Java ArrayList ntxiv ntau yam Tom qab ntawd, lub cov ntsiab lus ntawm cov npe tau ntxiv rau daim ntawv thib peb nrog rau addAll() txoj kev. xim 3. addAll(colours1); Txoj kev addAll() ntxiv tag nrho cov cov ntsiab lus mus rau qhov kawg ntawm daim ntawv teev npe.

Tsis tas li ntawd, koj yuav ntxiv cov txiaj ntsig rau ArrayList li cas? Code 1:

  1. ArrayList arr = new ArrayList(); arr. ntxiv(3); arr. add("ss");
  2. ArrayList arr = new ArrayList(); arr. ntxiv(3); arr. add("ss");
  3. ArrayList arr = new ArrayList(); arr. add(new Integer(3)); arr. add(new String("ss"));

Ib yam li ntawd, koj tuaj yeem nug, ua li cas koj ntxiv cov khoom rau ArrayList hauv Java?

ArrayList siv lub List Interface. Rau ntxiv ib qho chaw mus rau qhov kawg ntawm ib qho ArrayList siv: boolean ntxiv (E elt); // Ntxiv ib qho kev siv rau ib qho khoom elt mus rau qhov kawg ntawm qhov ArrayList , // nce loj los ntawm ib qho. Lub peev xwm yuav nce yog tias xav tau. // Ib txwm rov qab muaj tseeb.

Peb puas tuaj yeem khaws ntau hom ntaub ntawv hauv ArrayList?

Java suav nrog ob qho tib si Array thiab ib qho ArrayList chav kawm. Lawv yog txhua tus "sau ntawm ntau cov khoom", yog li hais, tab sis lawv kuj heev txawv . Ib ArrayList tuaj yeem fluctuate nyob rau hauv loj raws li tej yam ntxiv los yog tshem tawm. Ib leeg ArrayList kuj muaj peev xwm tuav ntau yam ntau hom ntawm cov khoom.

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