Java小程序代码.docx
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Java小程序代码
/**第一个程序*/
publicclassWelcome
{
publicstaticvoidmain(String[]args)
{
System.out.println("这是你的第一个程序,欢迎你走入Java的大门");
}
}
/**学生信息导入*/
classStudentTest
{
publicstaticvoidmain(String[]args)
{
StudentaStudent=newStudent();
aStudent.setName("张楠");
aStudent.setStudentNum("20030408");
System.out.println("学生的姓名是:
"+aStudent.getName()+",学号是:
"+aStudent.getStudentNum());
}
}
classPeople
{
privateStringname;
publicStringgetName(){
returnname;
}
publicvoidsetName(StringstrName)
{
name=strName;
}
}
classStudentextendsPeople
{
privateStringstudentNum;
publicStringgetStudentNum()
{
returnstudentNum;
}
publicvoidsetStudentNum(StringstrStudentNum)
{
studentNum=strStudentNum;
}
}
/**移位运算符测试*/
publicclassBitMotion
{
publicstaticvoidmain(String[]args)
{
inta=15;
intb=2;
intx=a<
inty=a>>b;
intz=a>>b;
System.out.println(a+"<<"+b+"="+x);
System.out.println(a+">>"+b+"="+y);
System.out.println(a+">>>"+b+"="+z);
}
}
/*
*测试位的四种运算
*/
publicclassBitOperation
{
publicstaticvoidmain(String[]args)
{
inta=15;
intb=2;
intx=a&b;
inty=a|b;
intz=a^b;
intr=~x;
System.out.println(a+"&"+b+"="+x);
System.out.println(a+"|"+b+"="+y);
System.out.println(a+"^"+b+"="+z);
System.out.println("~"+x+"="+r);
}
}
/*
*测试boolean型数据
*/
publicclassBooleanTest
{
publicstaticvoidmain(String[]args)
{
inta=20;
intb=30;
booleanx,y,z;
x=(a>b);
y=(a
z=((a+b)==50);
System.out.println("x="+x);
System.out.println("y="+y);
System.out.println("z="+z);
}
}
/*
*测试不同数制表现形式及系统的自动转化功能
*/
publicclassByteTest
{
publicstaticvoidmain(String[]args)
{
bytex=22;//十进制
bytey=022;//八进制
bytez=0X22;//十六进制
System.out.println("转换成十进制,x="+x);
System.out.println("转换成十进制,y="+y);
System.out.println("转换成十进制,z="+z);
}
}
/*
*测试char型与整数的转换
*/
publicclassCharTest
{
publicstaticvoidmain(String[]args)
{
charx='M';
chary='\120';//请注意数字在输出时被转化成为字符
charz='V';
System.out.println("字符x="+x);
System.out.println("字符y="+y);
System.out.println("数值Z="+(x+z));
}
}
/*
*常量的使用
*/
publicclassConstants
{
publicstaticvoidmain(String[]args)
{
finaldoubleCM_PER=3.14;
doubleradius=5;
System.out.println("thecircleareais"+CM_PER*radius*radius);
}
}
/*
*类常量的使用
*/
publicclassConstants2
{
staticfinaldoubleCM_PER=3.14;
publicstaticvoidmain(String[]args)
{
doubleradius=5;
System.out.println("thecircleareais"+CM_PER*radius*radius);
}
}
/*
*两个整数相除及求余数
*/
publicclassDivide
{
publicstaticvoidmain(String[]args)
{
inta=15;
intb=2;
doublec=2;
System.out.println(a+"/"+b+"="+(a/b));
System.out.println(a+"%"+b+"="+(a%b));
System.out.println(a+"/"+c+"="+(a/c));
System.out.println(a+"%"+c+"="+(a%c));
}
}
/*
*测试double型数据类型
*/
publicclassDoubleTest
{
publicstaticvoidmain(String[]args)
{
doublex=22;
doubley=42.6D;
doublez=x*y;
System.out.println("double型x="+x);
System.out.println(x+"*"+y+"="+z);
}
}
/*
*测试float型数值
*/
publicclassFloatTest
{
publicstaticvoidmain(String[]args)
{
floatx=22.2F;
floaty=42.6F;
floatz=x*y;
System.out.println(x+"*"+y+"="+z);
}
}
/*
*测试全局变量的操作
*/
publicclassGlobalVar
{
inta=10;
doubleb=20;
publicstaticvoidmain(String[]args)
{
GlobalVarglobalVar=newGlobalVar();
System.out.println("thevaluea="+globalVar.a);
globalVar.print();
System.out.println("afterchangedthevaluea="+globalVar.a);
}
publicvoidprint()
{
System.out.println("theglobalvariable a="+a+",b="+b);
a=30;
System.out.println("theglobalvariable a="+a+",b="+b);
}
}
/*
*测试基本类型的初始化
*/
publicclassInitPrimitive1
{
bytea;
shortb;
intc;
longd;
floate;
doublef;
charg;
booleanh;
publicstaticvoidmain(String[]args)
{
InitPrimitive1aInit=newInitPrimitive1();
aInit.print();
}
publicvoidprint()
{
System.out.println("字节型,a="+a);
System.out.println("短整型,b="+b);
System.out.println("整数型,c="+c);
System.out.println("长整型,d="+d);
System.out.println("单精度型,e="+e);
System.out.println("双精度型,f="+f);
System.out.println("字符型,g="+g);
System.out.println("布尔型,h="+h);
}
}
/*
*测试基本类型的初始化
*/
publicclassInitPrimitive2
{
publicstaticvoidmain(String[]args)
{
InitPrimitive2aInit=newInitPrimitive2();
aInit.print();
}
publicvoidprint()
{
bytea;
shortb;
intc;
longd;
floate;
doublef;
charg;
booleanh;
System.out.println("字节型,a="+a);
System.out.println("短整型,b="+b);
System.out.println("整数型,c="+c);
System.out.println("长整型,d="+d);
System.out.println("单精度型,e="+e);
System.out.println("双精度型,f="+f);
System.out.println("字符型,g="+g);
System.out.println("布尔型,h="+h);
}
}
/*
*测试局部变量的操作
*/
publicclassLocalVar
{
publicstaticvoidmain(String[]args)
{
LocalVarlocalVar=newLocalVar();
System.out.println("thevaluea="+localVar.a);
localVar.print();
System.out.println("afterchangedthevaluea="+localVar.a);
}
publicvoidprint()
{
inta=10;
doubleb=20;
System.out.println("thelocalvariable a="+a+",b="+b);
a=30;
System.out.println("thelocalvariable a="+a+",b="+b);
}
}
/*
*测试局部变量的操作
*/
publicclassLocalVar2
{
publicstaticvoidmain(String[]args)
{
LocalVar2localVar=newLocalVar2();
localVar.print();
}
publicvoidprint()
{
inta=10;
doubleb=20;
System.out.println("thelocalvariable a="+a+",b="+b);
a=30;
System.out.println("thelocalvariable a="+a+",b="+b);
}
}
/*
*逻辑运算符测试
*/
publicclassLogicSign
{
publicstaticvoidmain(String[]args)
{
booleanx,y,z,a,b;
a='A'>'b';
b='R'!
='r';
x=!
a;
y=a&&b;
z=a||b;
System.out.println("x="+x);
System.out.println("y="+y);
System.out.println("z="+z);
}
}
/*
*关系运算符测试
*/
publicclassRelationTest
{
publicstaticvoidmain(String[]args)
{
booleanx,y,z;
inta=15;
intb=2;
doublec=15;
x=a>b;//true;
y=a
z=a!
=b;//true;
System.out.println("x="+x);
System.out.println("y="+y);
System.out.println("z="+z);
}
}
/*
*测试自增、自减操作
*/
publicclassSelfAction
{
publicstaticvoidmain(String[]args)
{
intx=10;
inta=x+x++;
System.out.println("a="+a);
System.out.println("x="+x);
intb=x+++x;
System.out.println("b="+b);
System.out.println("x="+x);
intc=x+x--;
System.out.println("c="+c);
System.out.println("x="+x);
intd=x+--x;
System.out.println("d="+d);
System.out.println("x="+x);
}
}
/*
*短路现象测试
*/
publicclassShortCircuit
{
publicstaticvoidmain(String[]args)
{
ShortCircuita=newShortCircuit();
if(a.test1(0)&&a.test2
(2)&&a.test3
(2))
{
System.out.println("thestatementistrue!
");
}else
{
System.out.println("thestatementisfalse!
");
}
}
publicbooleantest1(intvalue1)
{
System.out.println("test1("+value1+")");
System.out.println("result:
"+(value1<1));
returnvalue1<1;
}
publicbooleantest2(intvalue2)
{
System.out.println("test2("+value2+")");
System.out.println("result:
"+(value2<2));
returnvalue2<2;
}
publicbooleantest3(intvalue3)
{
System.out.println("test3("+value3+")");
System.out.println("result:
"+(value3<3));
returnvalue3<3;
}
}
/*
*测试传址引用的实质
*/
publicclassStudent
{
StringstrName;
publicstaticvoidmain(String[]args)
{
StudentaStudent=newStudent();//得到对象Student类的一个句柄aStudent
aStudent.setStudentName("张楠");
System.out.println("aStudentnameis"+aStudent.getStudentName());
StudentbStudent=aStudent;//将aStudent句柄复制给nextStudent
bStudent.setStudentName("唐僧");
System.out.println("bStudentnameis"+bStudent.getStudentName());
Stringname=aStudent.getStudentName();//再看一下句柄aStudent的内容是否改变
System.out.println("afterbStudenttheaStudentnameis"+name);
}
publicvoidsetStudentName(Stringname)
{
strName=name;
}
publicStringgetStudentName()
{
returnstrName;
}
}
/*
*强制转型测试
*/
publicclassTypeTran
{
publicstaticvoidmain(String[]args)
{
intx;
doubley;
x=(int)22.5+(int)34.7;//强制转型可能引起精度丢失
y=(double)x;
System.out.println("x="+x);
System.out.println("y="+y);
}
}
/*
*测试传值引用的实质
*/
publicclassValueReference
{
inta=10;
publicstaticvoidmain(String[]args)
{
ValueReferenceaValue=newValueReference();
aValue.print();
}
publicvoidprint()
{
intb=a;//我们将a的值传给了a
System.out.println("beforechangedvaluea="+a+",b="+b);
a=30;
System.out.println("afterchangedvalue a="+a+",b="+b);
}
}
/*
*中断测试
*/
publicclassBreakTest
{
publicstaticvoidmain(String[]args)
{
for(inti=1;i<20;i++)
{
if(i==10)
break;
System.out.print(""+i);
}
System.out.println("\ntheReptationisover!
");
}
}
/*
*while循环控制结构的测试
*/
publicclassBuyHouse
{
publicstaticvoidmain(String[]args)
{
finaldoubleHOUSEFUND=200000;
doublesalary=2000;
doublefund=0;
intyears=1;
while(fund{
fund+=salary*0.05*12;
years++;
salary=salary*