Java入门基础代码.doc

classDoubleVariableDemo{ publicstaticvoidmain(Stringargs[]){ doubledRadius=; doubledArea=*dRadius*dRadius; ("半径为2的圆的面积:"+dArea); }}例1-{ publicstaticvoidmain(Stringargs[]){ finalbooleanBFLAG=true; if(BFLAG) ("AlwaysPrintOutMe!"); else ("NeverPrintOutMe!"); }}例1-{ publicstaticvoidmain(Stringargs[]){ shortx=1,y=2,z; //错误代码//z=x+y; //正确代码 z=(short)(x+y); (z); }}例1-{ publicstaticvoidmain(Stringargs[]){ finalbytenMaxValue_1=100; finalshortnMaxValue_2=200; finalintnMaxValue_3=300; finallongnMaxValue_4=400; ("整数常量的nMaxValue_1值"+nMaxValue_1); ("整数常量的nMaxValue_2值"+nMaxValue_2); ("整数常量的nMaxValue_3值"+nMaxValue_3); ("整数常量的nMaxValue_4值"+nMaxValue_4); //nMaxValue_1=nMaxValue_1+1;不能更改常量的值 }}例1-{ publicstaticvoidmain(Stringargs[]){ intnOp1=2; floatfOp2=; floatfResult=nOp1*fOp2; ("混合运算结果:"+fResult); }}例1-{ publicstaticvoidmain(Stringargs[]){ ("IntegerArithmetic"); inta=1+1; intb=a*3; intc=b/4; intd=c-a; ("c="+c); ("d="+d); ("\nFloatingPointArithmetic"); doubleda=1+1; doubledb=da*3; doubledc=db/4; doubledd=dc-a; ("dc="+dc); ("dd="+dd); intx=42; doubley=; ("xmod10="+x%10); ("ymod10="+y%10); }}例1-{ publicstaticvoidmain(Stringargs[]){ intnOperator1=5; intnOperator2=10; if((nOperator1>4)&&(nOperator2>9)) ("nOperator1大于4并且nOperator2大于9"); else ("逻辑关系判断不成立"); }}例1-{ publicstaticvoidmain(Stringargs[]){ booleana=true; booleanb=false; booleanc=a|b; boolean