string split problem

[roofninja]

I don't know enough of Java, so I am just stabbing in the dark here. I am lost. What this program should do is get the local IP and display only the 2nd octet of the IP.

It doesn't compile and the error message is"incompatible types" for where the arrow is in the code and it is pointing at the "(". Required String???

import java.net.*;
import java.io.*;
import javax.swing.JOptionPane;
public class findip {
public static void main(String[] args) throws IOException{
	String myip,myip2;
	InetAddress thisIp =InetAddress.getLocalHost();
	myip=thisIp.getHostAddress();
	myip2=myip.split(".");  //<--------
	//myip2=String.split(myip,".");
	//need to just show or have 2nd octet
	JOptionPane.showMessageDialog(null,"IP:__"+myip+"\n\nNum:__"+myip2);
}}

[Waflix]

Your problem is that, after having split the string, the information is being saved as an array. Here's your code, but now corrected.

import java.net.*;
import java.io.*;
import javax.swing.JOptionPane;
public class findip {
public static void main(String[] args) throws IOException{
    String myip;
    String[] myip2;
    InetAddress thisIp =InetAddress.getLocalHost();
    myip=thisIp.getHostAddress();
    myip2=myip.split(".");  //<--------
    //myip2=String.split(myip,".");
    //need to just show or have 2nd octet
    JOptionPane.showMessageDialog(null,"IP:__"+myip+"\n\nNum:__"+myip2);
}}

This website helped gave me a better understanding of arrays and how they work:
All About Java Arrays

[sunde887]

Can you copy and paste the error?

[Waflix]

If I'm not mistaken:

findip.java:9: incompatible types
found : java.lang.String[]
required: java.lang.String
myip2=myip.split("."); //<--------
^
1 error

[sunde887]

As Waflix said, and the error hints, you tried to put a String array in a String. A String array is an array such that each element is itself a String.

[roofninja]

I haven't gotten to arrays yet, so this is more complicated that what I think I understand. I will revisit this thread when I have more info.

[roofninja]

I did finally figure out what I was doing wrong with this string split problem. First, I didn't have the String array setup correctly and then I wasn't using the split correctly.

This is what I like about programming. There is always another challenge around the corner.

import java.net.*;
import java.io.*;
import javax.swing.JOptionPane;
public class findip {
public static void main(String[] args) throws IOException{
	String[] myip2=new String[3];
	InetAddress thisIp =InetAddress.getLocalHost();
	myip2=thisIp.getHostAddress().split("\\.");
	JOptionPane.showMessageDialog(null,"IP:__"+myip2[1]);
}}

[DarrylBurke]

You don't need to assign the array variable to a new array that is never used. Simply declare and assign it:

    InetAddress thisIp =InetAddress.getLocalHost();
    String[] myip2=thisIp.getHostAddress().split("\\.");

db

[roofninja]

I am reading and learning from an old book. So I am sure some of the things that I am learning, are out dated. I will remember this. Thanks.