????1).???????η??????????3????
?????????
???????
?????????????
????public
???????е?
??????????????????
????protected
???????????
??????????????
????private
??????е?
????????????
????2).?????????????????????????????????????????????6????
?????????
???????
?????????????
????class
??????
????publicclassA(){}???????????????????壬?????????????????
????interface
???????
????publicinterfaceB(){}?????????з????壬????????????????????????????“:”??β
????abstract
????????????
????publicabstractclassC(){}???????????м???????????????????????????
????implements
???????
??????????????????publicclassAinterfaceB(){}
????extends
???????
??????????????publicclassAextendsD(){}
????new
?????????????
????Aa=newA();A????????
????3).???????????2????
?????????
???????
?????????????
????import
???????????????
?????????????????Щ???????????????????ctrl+shift+o????????????????????????????ctrl+??????????????????????????磺JFrame??????????????
????importjavax.swing.JFrame;
????package
???????????????
???????????й??????????????????????????磺packagejavake.flycat.draw002;
????4).????????????????12????
?????????
???????
?????????????
????byte
?????????
????8bit
????char
?????????
????16bit
????boolean
??????????
????--
????short
??????????
????16bit
????int
????????
????32bit
????float
??????????
????32bit
????long
??????????
????64bit
????double
?????????
????64bit
????void
?????????
????publicvoidA(){}?????????????????return????
????null
???????
????true
??????
????false
??????
????5).?????????????????????12????
?????????
???????
?????????????
????if
???????
????if(){}???С??????????????????????????????
????else
????????????
????????if??????÷????
????while
?????????????
????while?????do??while(){}
????for
?????????????????
????for(;;){}
????switch
????????
????switch(????)
????{
????case????????1:???1;
????....
????case????????2:???2;
????default:???;
????}
????default???????з????case???????default??????????.
????case?????????????????.
????switch?????ж????????????int??byte??char??short?????????????????.
????case
????????????????
????default
???????
????do
????????
????????while????
????break
???????????
????continue
????????
?????ж?????????????????????
????return
????????
????return????????????
????instanceof
???????
????????????????????==??>??<????????????????????????????????????????????boolean?????????