开发实例利用做一个简单的计算器物业

两个类。还只是完成＋、－、×、÷运算而已。GUI只是用了AWT，很简单，相信一看就能懂了。

va

以下是引用片段：

publicclassCalculator{

privateStringresult=\"0\";

第二种情况：做整站排名的话 privateintop=0,add=1,sub=2,mul=3,div=4;

privatedoublestringToDouble(Stringx){

doubley=rseDouble(x);

returny;

}

privatevoidoperate(Stringx){

doublex1=stringToDouble(x);

doubley=stringToDouble(result);

switch(op){

case0:

result=x;

break;

case1:

result=lueOf(y+x1);

break;

case2:

result=lueOf(y-x1);

break;

case3:

result=lueOf(y*x1);

break;

case4:

if(x1!=0){

result=lueOf(y/x1);

}else{

result=\"Thedivisorcan\'tbezero!\";

}

break;

}

}

publicStringopAdd(Stringx){

operate(x);

op=add;

returnresult;

}

publicStringopSubtract(Stringx){

operate(x);

op=sub;

returnresult;

}

publicStringopMultiply(Stringx){

operate(x);

op=mul;

returnresult;

}

publicStringopDivide(Stringx){

operate(x);

op=div;

returnresult;

}

publicStringopEquals(Stringx){

operate(x);

op=0;

returnresult;

}

publicvoidopClean(){

op=0;

result=\"0\";

}

}