Java Reference
In-Depth Information
String operation = args[1];
double result = compute(n1, n2, operation);
// Print the result
System.out.println(args[0] + args[1] + args[2] + "=" + result);
}
public static double compute(double n1, double n2, String operation)
{
// Initialize the result with not-a-number
double result = Double.NaN;
switch (operation) {
case "+":
result = n1 + n2;
break;
case "-":
result = n1 - n2;
break;
case "*":
result = n1 * n2;
break;
case "/":
result = n1 / n2;
break;
default:
System.out.println("Invalid operation:" + operation);
}
return result;
}
public static void printUsage() {
System.out.println("Usage: java com.jdojo.array.Calc expr");
System.out.println("Where expr could be:");
System.out.println("n1 + n1");
System.out.println("n1 - n2");
System.out.println("n1 * n2");
System.out.println("n1 / n2");
System.out.println("n1 and n2 are two numbers");
}
}
You may use the
Calc
class as follows.
java com.jdojo.array.Calc 3 + 7
java com.jdojo.array.Calc 78.9 * 98.5
