[BobboJC]

I'm working on a Program for my computer class. I understand what is going on, but have a hard time writing my own code. The requirements for this program are found at http://149.149.136.7...10programs.html and Program Number 1. I understand what I am supposed to do, but am having an extremely hard time implementing it. I do not want a hand-out as that will not help me in the end, but some guidance would be appreciated. I've been working on it for an hour and here is what I have at this point:

//*************************************************************************
// Secant.java Author: Robert Young
//
//
//*************************************************************************

public class Secant
{

public static void main (String[] args)
{
string temp;
string filename;

temp=getInput("Would you like to specify your polynomial with a file (y or n)? ");

if (temp=y)
{
filename=getInput("Enter the file name: ");
}
}

public static double secant(Poly poly, double x0, double x1, int iter) //returns the result of the secant method
{

}

public static Poly getPoly(int degree) //user inputs the coefficients of the powers of x from 0 to degree
{
return Keyboard.readInt(prompt);
}

public static String displayPoly(Poly poly) //displays the polynomial (nonzero coeffs only)
{

}
}

It is definately not much and much may not be correct. My AIM name is bjy562 and MSN is [email protected]. Again, I do not want a hand-out, but some help. It would be greatly appreciated.

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if (temp=y)
{
filename=getInput("Enter the file name: ");
}

This will not work. First of all, the = operator is an assignment operator. It will pass a reference of y to temp. Then, y isn't a variable, so you'll get an error. Also, you'll get an error even if y was declared, because conditionals resolve to boolean values; temp=y does not resolve to a boolean value. You need to change that to:

if (temp.equals("y")) {
	filename = getInput("Enter the file name: ");
}

Assuming that getInput(String) is declared in your class.

Another thing... you cannot create a string with string because string is not a class. String is.

import java.util.Scanner;

public class Secant {
	/** for user input */
	static private Scanner scanner = new Scanner(System.in);
	
	/** main entry point of the program */
	static public void main(String[] args) {
		/** prompt user to see whether they would like to read from a file or not */
		System.out.print("Would you like to specify your polynomial with a file (y or n)? ");
		
		/** take the first character of the user's response, if it equals 'y', then wantsFile will be true */
		boolean wantsFile = (scanner.next().charAt(0) == 'y');
		
		if (wantsFile) {
			/** prompt user for file name */
			System.out.print("Enter the file name: ");
			
			/** create a file out of the user's input (which will be the path of the file) */
			File file = new File(scanner.next());
		}
	}
	
	/**
	 * @param poly  the polynomial to use
	 * @param x0	starting function value for root finding
	 * @param x1	starting function value for root finding
	 * @param iter  the number of times to iterate
	 */
	static public double secant(Poly poly, double x0, double x1, int iter) {
	}
	
	// etc...
}

I'm not exactly sure on what your stuck with. Please be more specific.

Hope this helps.

Edited by destin, 12 February 2006 - 10:42 PM.

[destin]

if (temp=y)
{
filename=getInput("Enter the file name: ");
}

This will not work. First of all, the = operator is an assignment operator. It will pass a reference of y to temp. Then, y isn't a variable, so you'll get an error. Also, you'll get an error even if y was declared, because conditionals resolve to boolean values; temp=y does not resolve to a boolean value. You need to change that to:

if (temp.equals("y")) {
	filename = getInput("Enter the file name: ");
}

Assuming that getInput(String) is declared in your class.

Another thing... you cannot create a string with string because string is not a class. String is.

import java.util.Scanner;

public class Secant {
	/** for user input */
	static private Scanner scanner = new Scanner(System.in);
	
	/** main entry point of the program */
	static public void main(String[] args) {
		/** prompt user to see whether they would like to read from a file or not */
		System.out.print("Would you like to specify your polynomial with a file (y or n)? ");
		
		/** take the first character of the user's response, if it equals 'y', then wantsFile will be true */
		boolean wantsFile = (scanner.next().charAt(0) == 'y');
		
		if (wantsFile) {
			/** prompt user for file name */
			System.out.print("Enter the file name: ");
			
			/** create a file out of the user's input (which will be the path of the file) */
			File file = new File(scanner.next());
		}
	}
	
	/**
	 * @param poly  the polynomial to use
	 * @param x0	starting function value for root finding
	 * @param x1	starting function value for root finding
	 * @param iter  the number of times to iterate
	 */
	static public double secant(Poly poly, double x0, double x1, int iter) {
	}
	
	// etc...
}

I'm not exactly sure on what your stuck with. Please be more specific.

Hope this helps.

Edited by destin, 12 February 2006 - 10:42 PM.

[BobboJC]

Hi Destin,

Thank you for the reply, it is helpful. Our prof makes us use a class called Keyboard instead of the Scanner class. Hence the return Keyboard.readDouble(prompt). The program is due tomorrow, and I've just hit a wall. I will continue to work on it in the morning, but again, thank you for your help.