My lines won't work!!!

Hi every one,

i'm new to java programming. I just started using Sams teach yourself Java in 21 days. I've just completed day 4th but i can't solve the second exercise which was to create a class that takes words for the first 10 numbers ("one" up to "ten") and converts them into a single long integer by using a switch statement for the conversion and command-line arguments for the words. I found the soluce on the book's web site but i want the code i wrote to work for i know there isn't only one single way to solve the problem. Here i send you my codes, can you please tell me what went wrong. Thank you.

Quote:

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please tell me what went wrong.

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Its better to post the code so all can read vs attaching a file.

Quote:

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tell me what went wrong.

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Can you tell us why you're not happy with the output from the program? Show the output and explain.

In case anyone didn't want to open the text file (Which was a pain to read) I fixed it up a little.

Here it is:

Code :

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public class WordToNumber {
	public static void main (String[] arguments) {
 
		long num = 0;
		String str1 = "zero";
 
		if (arguments.length > 0) {
			str1 = (String)arguments[0];
 
			for (int i = 0; i < arguments.length; i++) {
				switch (i) {  //***This confuses me here. Didn't you just use the i in the line above?
					case 1:
						if (str1 == "one") {
							num = 1L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 2:
						if (str1 == "two") {
							num = 2L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 3:
						if (str1 == "three") {									
							num = 3L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 4:
						if (str1 == "four") {									
							num = 4L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 5:
						if (str1 == "five") {									
							num = 5L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 6:
						if (str1 == "six") {								   	
							num = 6L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 7:
						if (str1 == "seven") {									
							num = 7L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 8:
						if (str1 == "eigth") {									
							num = 8L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 9:
						if (str1 == "nine") {									
							num = 9L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					case 10:
						if (str1 == "ten") {								   	
							num = 10L;
							System.out.println(str1 + " is equivalent to " + num);
						}
						break;
					default:
						if (str1 == "zero") {									
							num = 0L;
							System.out.println(str1 + " is equivalent to " + num);
						}
				}
			}
		}
	}
}

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What I don't understand (And I'm a bit of a noob so maybe you can explain this to me OP) is where the program is reading in the string from. It also looks to me like the switch is running off of the i you're using for the FOR loop? I could just be completely wrong/confused though.

I wanted to give it a go...hope it helps you

Code :

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import java.io.*;
 
public class wordToLong 
{
	public static void main(String[] args)
	{
		BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter stdOut = new PrintWriter(System.out, true);
 
		stdOut.print("Input string : ");
		stdOut.flush();
 
		try
		{
			String all_words = stdIn.readLine();
			String[] words = all_words.split(" ");
			String digits = new String();
 
			for(int i=0;i<words.length;++i)
			{
				switch(words[i].charAt(0))
				{
				case 'o':
					digits = digits.concat("1");
					break;
				case 't':
					switch(words[i].charAt(1))
					{
					case 'w':
						digits = digits.concat("2");
						break;
					case 'h':
						digits = digits.concat("3");
						break;
					case 'e':
						digits = digits.concat("10");
						break;
					}
					break;
				case 'f':
					switch(words[i].charAt(1))
					{
					case 'o':
						digits = digits.concat("4");
						break;
					case 'i':
						digits = digits.concat("5");
						break;
					}
					break;
				case 's':
					switch(words[i].charAt(1))
					{
					case 'i':
						digits = digits.concat("6");
						break;
					case 'e':
						digits = digits.concat("7");
						break;
					}
					break;
				case 'e':
					digits = digits.concat("8");
					break;
				case 'n':
					digits = digits.concat("9");
					break;
 
				}
			}
 
			long theFinalLong = Long.parseLong(digits);
			stdOut.println("< " + theFinalLong + " >");
		}
		catch(IOException e)
		{
			stdOut.println("Error : " + e.getMessage());
		}
		finally
		{
			try
			{
				stdIn.close();
				stdOut.close();
			}
			catch(IOException e)
			{
				System.out.println("Cannot close streams !");
			}
		}
 
	}
 
}

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Sample runs:
Input : one three six five five
Output : < 13655 >

Not much error checking. Any word beginning with o is a 1 etc.
But given the requirements to use a switch statement there probably isn't much choice.
You could add a test to see if the String starting with 'o' was 'one' and give an error message.

Quote:

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where the program is reading in the string from.

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The String is coming from the command line arguments passed to main().

Ah okay. Sorry if that seemed like a stupid question, haven't coded anything like that in the narrow scope of the class I'm in.