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Yuav ua li cas kho qhov tsis suav tus pointer kev zam hauv Java?
Yuav ua li cas kho qhov tsis suav tus pointer kev zam hauv Java?

Video: Yuav ua li cas kho qhov tsis suav tus pointer kev zam hauv Java?

Video: Yuav ua li cas kho qhov tsis suav tus pointer kev zam hauv Java?
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Anonim

Cov no tuaj yeem yog:

  1. Invoking ib txoj kev los ntawm a null khoom.
  2. Nkag mus lossis hloov kho a null qhov chaw.
  3. Noj qhov ntev ntawm null , zoo li nws yog ib qho array.
  4. Nkag mus los yog hloov kho cov slots ntawm null khoom, zoo li nws yog ib qho array.
  5. pov null , zoo li nws yog tus nqi Throwable.
  6. Thaum koj sim synchronize dhau ib null khoom.

Tsis tas li ntawd, kuv yuav kho qhov kev zam tsis tau tus pointer li cas?

Cov no suav nrog:

  1. Hu rau txoj kev piv txwv ntawm ib qho khoom tsis raug.
  2. Nkag mus lossis hloov kho qhov chaw ntawm ib qho khoom tsis raug.
  3. Noj qhov ntev ntawm null zoo li nws yog ib qho array.
  4. Kev nkag los yog hloov kho cov slots ntawm null zoo li nws yog ib qho array.
  5. Pov tseg null zoo li nws yog tus nqi Throwable.

Ib sab saum toj no, yog vim li cas kuv thiaj li tau txais ib qho kev zam tus pointer null hauv Java? NullPointerException yog RuntimeException. Hauv Java , tshwj xeeb null tus nqi tuaj yeem raug xa mus rau qhov khoom siv. NullPointerException raug pov tseg thaum daim ntawv thov sim siv cov khoom siv uas muaj cov null tus nqi. Hu rau tus qauv piv txwv ntawm cov khoom xa los ntawm a null siv.

Ib yam li ntawd, kuv yuav ua li cas thiaj li tshem tau qhov tsis muaj qhov tshwj xeeb hauv Java?

Java Cov Lus Qhia thiab cov kev coj ua zoo tshaj plaws kom tsis txhob NullPointerException

  1. Hu rau equals() thiab equalsIgnoreCase() txoj kev ntawm String paub literal es tsis paub khoom.
  2. Nyiam valueOf() dhau rauString() qhov twg ob qho tib si rov qab los tib yam.
  3. Siv cov kev nyab xeeb null thiab cov tsev qiv ntawv.
  4. Tsis txhob xa rov qab null los ntawm txoj kev, es tsis txhob xa rov qab khoob khoob lossis khoob array.

Dab tsi yog null pointer kev zam hauv Java piv txwv?

Null Pointer Exception hauv Java Programming. NullPointerException yog runtime kev zam thiab nws raug pov tseg thaum daim ntawv thov sim siv cov khoom siv uas muaj a null tus nqi. Rau piv txwv , siv ib txoj kev ntawm a null siv.

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