问题是这样的:编写一个程序,求解一元二次方程:a*x*x+b*x+c=0.参数a、b及c从命令行输入。
然后我写的程序是public class a001{
public static void main(String []args){
if(args.length!=3)
{
System.out.println("Usage: java SolveQuadratic aCoef bCoef cCoef \nExample java a001 1 2 1");
System.exit(-1);
}
double a,b,c;
double a=double.parseDouble(args[0]);
if(Math.abs(a)<Math.pow(10,-6))
System.out.println("a=0,This is not a quadratic");
System.exit(-1);
double b=double.parsedouble(args[1]);
double c=double.parsedouble(args[2]);
double d=b*b-4*a*c;
System.out.println("This is a quadratic");
if(Math.abs(d)<Math.parseDouble(10,-6))
System.out.println("this quadratic have two equal roots"+(-b)/(2*a));
if(d>0){
System.out.println("The first answer "+(-b-Math.sqrt(d))/2*a);
System.out.println("The second answer "+(-b+Math.sqrt(d))/2*a);
}
else
{ double e=(-b)/2*a;
double f=Math.sqrt((-d)/2*a);
System.out.println("The first answer "+e+"+"+f+"i");
System.out.println("The second answer "+e+"-"+f+"i");
}
}
}
然后提示说:double a=double.parseDouble(args[0]);double b=double.parsedouble(args[1]);double c=double.parsedouble(args[2]);这三句需要class,不知怎么解决。
谢谢您的关注。
然后我写的程序是public class a001{
public static void main(String []args){
if(args.length!=3)
{
System.out.println("Usage: java SolveQuadratic aCoef bCoef cCoef \nExample java a001 1 2 1");
System.exit(-1);
}
double a,b,c;
double a=double.parseDouble(args[0]);
if(Math.abs(a)<Math.pow(10,-6))
System.out.println("a=0,This is not a quadratic");
System.exit(-1);
double b=double.parsedouble(args[1]);
double c=double.parsedouble(args[2]);
double d=b*b-4*a*c;
System.out.println("This is a quadratic");
if(Math.abs(d)<Math.parseDouble(10,-6))
System.out.println("this quadratic have two equal roots"+(-b)/(2*a));
if(d>0){
System.out.println("The first answer "+(-b-Math.sqrt(d))/2*a);
System.out.println("The second answer "+(-b+Math.sqrt(d))/2*a);
}
else
{ double e=(-b)/2*a;
double f=Math.sqrt((-d)/2*a);
System.out.println("The first answer "+e+"+"+f+"i");
System.out.println("The second answer "+e+"-"+f+"i");
}
}
}
然后提示说:double a=double.parseDouble(args[0]);double b=double.parsedouble(args[1]);double c=double.parsedouble(args[2]);这三句需要class,不知怎么解决。
谢谢您的关注。
应该是
double a=Double.parseDouble(args[0]);