Scanner class question

[Rgfirefly24]

ok, so i want to input a Math equation say 3 * 2. Now if i remember right the * either comes out as a string or char. I was curious how to store this into a single array to be used in a switch case

now using a String[] just throws out incompatible types on the 3 and 2.... while int[] throws out incompatible types on the *. I didn't see anywhere in any documentation for the scanner class where you can do something along these lines char[] = scanner.nextChar(); Any ideas? and no parsing out each number etc wasn't an option in this lab smile.gif

[Zosden]

What I would do is something along the lines of 3 * 4 then when the user presses enter you take that string in and then just use the String class to parse it. For Example: Sorry I don't quite remember the scanner class so forgive me

String tempStr = What ever way you get the String.

int tempInt = tempStr.getNextInt(); // I think this is right check the api

if(tempStr.getNextChar.equals(*)
      //change your switch variable
// then your switch statement

case whatever: tempInt = tempInt * tempStr.getNextInt(); break;

[Rgfirefly24]

i have thought about doing it this way; however, it would require me to parse out the input instead of setting it equal to a single string. Now, i know that i can do it by using String[] args and doing comand line running as in:

java lab6 3 *4

but i need it to be an input that is presented after the program loads. It also needs to go into a single array to be used in the switch case

code:

/*James Bridgeford
	Lab 6
	this lab throws exceptions when a user imputs wrong input
*/

import javax.swing.*;
import java.lang.*;
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.Graphics;
import java.util.Scanner;


public class lab6 {
	/** main method no constructors **/
	public static void main(String[] args) throws IllegalArgumentException{
			//create the scanner
			Scanner scanner = new Scanner(System.in);

			//get input from user
			System.out.print("Enter an operation I.E 3 * 2");

			char[] input = scanner.next();

			/*for (int i=0;i<input1.length;i++){
				String[] input = String.parseString(input1);
			}*/

			if (input.length != 3)
				throw new IllegalArgumentException("Wrong Input: " + input[0]);


			else
			{
				int result = 0;

				switch(args[1].charAt(0)){
					case '+': 	result = (input[0]) + (input[2]);
								break;
					case '-':	result = (input[0]) - (input[2]);
								break;
					case '*':	result = (input[0]) * (input[2]);
								break;
					case '/':	result = (input[0]) / (input[2]);
								break;

				}
				System.out.println(input[0] + ' ' + input[1] + ' ' + input[2] + "=" + result);
			}
	}
}

[Rgfirefly24]

ok so basically I found out that using scanner.next() is only grabbing 5 instead of 5 * 3. if i try putting it in quotes it only grabs "5. if i try using single quotes it just grabs '5. I'm at a loss as to how to grab the whole input.

[Zosden]

This is correct use a while loop to get all the information

String tempStr = What ever way you get the String.

while(tempStr != null)
{
    int tempInt = tempStr.getNextInt(); // I think this is right check the api

    if(tempStr.getNextChar.equals(*)
         //change your switch variable
    // then your switch statement

    case whatever: tempInt = tempInt * tempStr.getNextInt(); break;
}

This way you could input any "correct" string and it would still work for any length of string.

[Rgfirefly24]

thanks mate, i just broke down and used a JOptionPane lol. It works that way by using String[] input = input1.split("\\s");