// Calculate the area of a circle
// Uses prompt.
// the purpose of this tutorial is to discover how to turn strings into numbers.
// and prompt for information from the command line.
// Code is public domain.
// Written T. McKeaveney, April 2008.
import std.conv;
import std.stdio;
import std.string;
import std.math;
const real pi = std.math.PI;
void main()
{
try
{
char [] chRadius;
float r;
writef("Enter the radius: ");
chRadius = chomp(readln(stdin));
r = toFloat(chRadius);
writefln("Circle area = %f", pi*r*r);
}
catch (Exception e)
{
writefln("catch %s", e.toString());
}
}
/* Common Errors:
1. tofloat instead of toFloat --> check capitilazation
2. std.math.pi / PI --> check capitilazation
3. forgetting the import
4. (real x float x float=>? ) needs to be cast to a specific type for printf
5. Declaring the Exception in the catch block
6. Removing the trailing white space imported from the command line
*/