if(a[i]==m){
System.out.println(i);
}
}
}
}
OddSum.java
publicclassOddSum{
publicstaticvoidmain(String[]args){
longresult=0;
for(inti=1;i<=99;i+=2){
result+=i;
}
System.out.println("result="+result);
}
}
Point3D.java
publicclassPoint3D{
doublex,y,z;
publicPoint3D(double_x,double_y,double_z){
x=_x;
y=_y;
z=_z;
}
publicvoidsetX(double_x){
x=_x;
}
publicdoubledistance(){
returnx*x+y*y+z*z;
}
publicstaticvoidmain(String[]args){
Point3Dp=newPoint3D(1.2,3.4,5.8);
p.setX(1.3);
System.out.println(p.distance());
}
}
TestAccess.java
T.java
publicclassT{
inti;
voidm(inti){
this.i=i;
}
voidm(shorti){
System.out.println("short");
}
publicstaticvoidmain(String[]args){
this.i=8;
Tt=newT();
t.m(5);
}
}
TestBreak.java
publicclassTestBreak{
publicstaticvoidmain(Stringargs[]){
intstop=4;
for(inti=1;i<=10;i++){
//当i等于stop时,退出循环
if(i==stop){
;
}
break;
System.out.println("i="+i);
}
}
}
TestCircle.java
classPoint{
privatedoublex;
privatedoubley;
Point(doublex1,doubley1){
x=x1;
y=y1;
}
publicdoublegetX(){returnx;}
publicdoublegetY(){returny;}
publicvoidsetX(doublei){x=i;}
publicvoidsetY(doublei){y=i;}
}
classCircle{
privatePointo;
privatedoubleradius;
Circle(Pointp,doubler){
o=p;
radius=r;
}
Circle(doubler){
o=newPoint(0.0,0.0);
radius=r;
}
booleancontains(Pointp){
doublex=p.getX()-o.getX();
doubley=p.getY()-o.getY();
if(x*x+y*y>radius*radius)returnfalse;
elsereturntrue;
}
publicvoidsetO(doublex,doubley){
o.setX(x);
o.setY(y);
}
publicPointgetO(){returno;}
publicdoublegetRadius(){returnradius;}
publicvoidsetRadius(doubler){radius=r;}
publicdoublearea(){
return3.14*radius*radius;
}
}
publicclassTestCircle{
publicstaticvoidmain(Stringargs[]){
Circlec1=newCircle(newPoint(1.0,2.0),2.0);
Circlec2=newCircle(5.0);
System.out.println("c1:
("+c1.getO().getX()+","
+c1.getO().getY()+"),"+c1.getRadius());
System.out.println("c2:
("+c2.getO().getX()
+","+c2.getO().getY()+"),"+c2.getRadius());
System.out.println("c1area="+c1.area());
System.out.println("c1area="+c2.area());
c1.setO(5,6);
c2.setRadius(9.0);
System.out.println("c1:
("+c1.getO().getX()+","
+c1.getO().getY()+"),"+c1.getRadius());
System.out.println("c2:
("+c2.getO().getX()+","
+c2.getO().getY()+"),"+c2.getRadius());
System.out.println("c1area="+c1.area());
System.out.println("c1area="+c2.area());
Pointp1=newPoint(5.2,6.3);
System.out.println(c1.contains(p1));
System.out.println(c1.contains(newPoint(10.0,9.0)));
}
}
TestConstruct.java
classPerson2{
privateStringname;
privateStringlocation;
Person2(Stringname){
this.name=name;
location="beijing";
}
Person2(Stringname,Stringlocation){
this.name=name;
this.location=location;
}
publicStringinfo(){
return
"name:
"+name+"location:
"+location;
}
}
classTeacherextendsPerson2{
privateStringcapital;
Teacher(Stringname,Stringcapital){
this(name,"beijing",capital);
}
Teacher(Stringname,Stringlocation,Stringcapital){
super(name,location);
this.capital=capital;
}
publicStringinfo(){
returnsuper.info()+"capital:
"+capital;
}
}
publicclassTestConstruct{
publicstaticvoidmain(String[]args){
Teachert=newTeacher("B","GG");
System.out.println(t.info());
}
}
TestConvert2.java
publicclassTestConvert2{
publicstaticvoidmain(String[]args){
inti=1,j=12;
floatf1=(float)0.1;//0.1f
floatf2=123;
longl1=12345678,l2=8888888888L;
doubled1=2e20,d2=124;
byteb1=1,b2=2,b3=127;
j=j+10;
i=i/10;
i=(int)(i*0.1);
charc1='a',c2=125;
byteb=(byte)(b1-b2);
charc=(char)(c1+c2-1);
floatf3=f1+f2;
floatf4=(float)(f1+f2*0.1);
doubled=d1*i+j;
floatf=(float)(d1*5+d2);
}
}
TestConvert.java
publicclassTestConvert{
publicstaticvoidmain(Stringarg[]){
inti1=123;
inti2=456;
doubled1=(i1+i2)*1.2;//系统将转换为double型运算
floatf1=(float)((i1+i2)*1.2);//需要加强制转换符
byteb1=67;
byteb2=89;
byteb3=(byte)(b1+b2);//系统将转换为int型运算,需要强制转换符
System.out.println(b3);
doubled2=1e200;
floatf2=(float)d2;//会产生溢出
System.out.println(f2);
floatf3=1.23f;//必须加f
longl1=123;
longl2=30000000000L;//必须加l
floatf=l1+l2+f3;//系统将转换为float型计算
longl=(long)f;//强制转换会舍去小数部分(不是四舍五入)
}
}
TestDigitCount.java
publicclassTestDigitCount{
publicstaticvoidmain(String[]args){
inti=34789;
doubled=3478.9765;
digitCount2(String.valueOf(i));
digitCount2(String.valueOf(d));
}
publicstaticvoiddigitCount(Strings){
intindex=s.indexOf(".");
if(index==-1){
System.out.println(s.length());
}else{
System.out.println("整数:
"+index+"\n"+"小数:
"+(s.length()-index-1));
}
}
publicstaticvoiddigitCount2(Strings){
Strings1=s.replace('.',',');
String[]ss=s1.split(",");
if(ss.length==1){
System.out.println(s1.length());
}elseif(ss.length==2){
System.out.println("整数:
"+ss[0].length()+"\n"+"小数:
"+ss[1].length());
}else{
System.out.println("FormatError!
");
}
}
}
TestEqual.java
publicclassTestEqual{
publicstaticvoidmain(String[]args){
Integeri1=newInteger
(1);
Integeri2=newInteger
(1);
System.out.println(i1==i2);
System.out.println(i1.equals(i2));
Maom1=newMao("A","A");
Maom2=newMao("A","A");
System.out.println(m1==m2);
System.out.println(m1.equals(m2));
}
}
classMao{
Stringname;
Stringcolor;
Mao(Stringn,Stringc){
name=n;color=c;
}
publicbooleanequals(Objectobj){
returntrue;
}
}
TestFormat.java
publicclassTestFormat{
publicstaticviodmain(String[]args){
System.out.println("ok");
System.out.println("hello");
inti=8+9;
for(inti=0;i<10;i++){
System.out.println(i);
System.out.println(i);
}
}
publicvoidm(){
System.out.println("ok");
}
publicvoidm2(){
System.out.println("ok");
}
publicvoidm3(){
System.out.println("ok");
}
publicvoidm4(){
}
}
TestIF.java
publicclassTestIF{
publicstaticvoidmain(String[]args){
inti=20;
if(i<20){
System.out.println("<20");
System.out.println("<20");
}elseif(i<40){
System.out.println("<40");
}elseif(i<60){
System.out.println("<60");
}else
System.out.println(">=60");
System.out.println(">=60");
}
}
TestInherit.java
classFatherClass{
publ