package examples;

/**
 * CS401 Example MyInteger
 * 
 * Simple demonstration of parsing a String into an int. If the String is not a
 * valid representation of an int, an exception is thrown. We will talk more
 * about exceptions a bit later.
 * 
 * @author Dr. Ramirez, PJ Dillon
 */
public class MyInteger
{
	// Simple integer parse function for non-negative numbers.
	public static int parseInt(String s)
	{
		int temp = 0;
		for (int i = 0; i < s.length(); i++)
		{
			temp = temp * 10; 							// Multiply previous answer by 10.  This
			                  							// "shifts" the digits to the left
			int newVal = s.charAt(i) - 48;  // Determine the next digit
			if (newVal < 0 || newVal > 9)   // Show an error if the digit
				throw (new NumberFormatException()); // is not valid
			temp = temp + newVal;  					// Add the next digit
		}
		return temp;
	}
}