public class TestArgs1{
public static void main(String [] args){
if(args.length<3){
System.out.println(
"usage:java test \"n1\"op\"n2\"");
System.exit(-1);
}
double d1=new double.parseDouble(args[0]);
double d2=new double.parseDouble(args[2]);
double d=0;
if (arg[1].equal("+")){
System.out.println(d="d1+d2");}
else if (arg[1].equal("x")){
System.out.println(d="d1xd2");}
else if (arg[1].equal("-")){
System.out.println(d="d1-d2");}
else {
System.out.println(Error!);
System.exit(-1);
}
System.out.println(d);
}
}
public static void main(String [] args){
if(args.length<3){
System.out.println(
"usage:java test \"n1\"op\"n2\"");
System.exit(-1);
}
double d1=new double.parseDouble(args[0]);
double d2=new double.parseDouble(args[2]);
double d=0;
if (arg[1].equal("+")){
System.out.println(d="d1+d2");}
else if (arg[1].equal("x")){
System.out.println(d="d1xd2");}
else if (arg[1].equal("-")){
System.out.println(d="d1-d2");}
else {
System.out.println(Error!);
System.exit(-1);
}
System.out.println(d);
}
}
System.out.println("usage:java test \"n1\"op\"n2\""); 输出的结果就是usage:java test "n1"op"n2"