Simple question on arrays
how do I get the length of an array? could you please
post an example? I've tried using the API but I don't
understand what it's saying
int[] myArray= {x, y, z, a, b);
int bar = myArray.length;
Similar Messages
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Im a couple days new in java, Ive been searching for an answer for hours and havent found a solution.
This is the mistake it shows (when trying to use any element of the array):
array required, but java.util.ArrayList <java.lang.String> found
The array is:
public static ArrayList<String> numList = new ArrayList<String>();
Im filling it this way: (so that it contains each word of a file in separate)
BufferedReader br = new BufferedReader(new FileReader("Archivo.txt"));
try
while(true)
String aLine = br.readLine();
if(aLine == null) throw new EOFException("Le?do todo el archivo.");
if(!aLine.equals(""))
StringTokenizer st = new StringTokenizer(aLine);
while(st.hasMoreTokens())
numList.add(st.nextToken());
}catch(EOFException e)
The problem comes when I try to use the elements of the array (in specific when trying to convert each element of the array to int, so that i can do math operations with them).
for example:
for (a=0; w>a; a++)
int x = Integer.parseInt(numList[a])
Can anyone help me with this? (where is the mistake and how to convert from string array elements to int)
Thank you // Muchas GraciasThe trouble is that you're confusing ArrayLists with arrays. They're not the same thing.
Currently you're making an ArrayList. If you want an array of String, do this:
String[] myArray = new String[50];
int i = 0;
while(st.hasMoreTokens()) {
myArray[i] = st.nextToken();
i++;
}Or perhaps better yet:
String[] numListArray = numList.toArray(new String[0]);But you really don't need an array for what you're doing. Use an Iterator.
Iterator<String> strings = numList.iterator();
while(strings.hasNext()) {
int x = Integer.parseInt(strings.next());
}You get the idea. Read the Collections tutorial about iterators. Read the language spec about arrays. Also look at the java.util.Arrays class. -
TMG Standalone Array simple question
hi everyone i have what i think is a simple question but i don't know if i'm missing something in all the tutorials about standalone arrays i've read.
i'm working with 2 tmg enterprise editions in 2008R2 in a test environment. both are on sp2 fully updated and a single 20 Mbit connection. i would like for this two tmg's to work for high availability using that connection only and i was able to join both in
a standalone array. here's how they're configured:
tmg01
internal nic ip range: 192.168.1.1/24
second internal nic: not connected at the moment, considering for intra-array network if needed later on (if anyone suggest is absolutely necessary)
external nic ip: dhcp supplied by isp.
tmg02
internal nic ip range: 192.168.1.2/24
second internal nic: not connected at the moment.
external nic: not connected. (where do i connect this one if i only have one modem for that 20 Mbit connection??)
i have read that the intra-array network is not absolutely necessary so i’m leaving those unplugged.
now, here’s my question, since they’re both already on an array, if tmg01 fails to deliver (let’s assume it has a hardware malfunction), how is tmg02 going to take over and connect to the external network if by definition my modem only accepts one cable? will
i have to be near the server and change the cable to the other nic in tmg02 for it to work or do i have to add something in between the modem and the two tmg’s?
is there something i’m missing? will i be needing 2 connections? maybe it’s too obvious or stupid and it just went passed me. i’m open to criticism and opinions.
thanksHi
Let follow the best practice.
In Production Normal setup for Full redundant Architecture, we need three servers, one for Array and other two servers for TMG for HA.
1 . TMG Array Server – Subnet Routable with Internal TMG Subnet ( You can also have this in any one TMG but best practice is to separate it )
2.
TMG – 1 – Two NIC, Internal / External
3.
TMG – 2 – Two NIC, Internal / External
Second Internal NIC is not required in your setup. So you can go with two NIC. External and Internal on two TMG
Join TMG 1 and TMG 2 to Single Array which is server 1. By this all the configuration you make on one TMG will sync with other TMG.
How TMG will handle in case of Server failure
You need to Create two NLB in TMG
One for Internal and one for External
Internal NLB
You need to create an Internal NLB, Since you are using 192.168.1.0 / 24 Network for Internal, assign an internal NLB as 192.168.1.3
If you want to use TMG as gateway for all internet connection, then you need to have default Route from internal network pointing to 192.168.1.3 which is TMG NLB internal IP
address
External NLB
Since you have not mentioned External Network, let’s assume you are using 10.10.10.0 / 24 and External Interface of TMG 1 is 10.10.10.1 and TMG 2 is 10.10.10.2, Then create
an External NLB and assign an IP address 10.10.10.3
You need to have a Switch in between your Router and TMG servers,
Connect TMG -1 and TMG – 2 External Interface NIC to Switch
On external NIC – Set gateway as Modem IP address of Both TMG
Connect an internet cable from modem to the same switch
Ensure that, you have a route to 10.10.10.0 /24
from Modem to External NLB IP address Ie 10.10.10.3
Now you don’t have to switch cables to Modem,
Good Luck !! -
A question about arrays (brace yourself this is a long post)
I am working on an assignment that is about generating a random rabbit race by using arrays:
Rabbit Race
Write a program to simulate a race between 4 rabbits (numbered 0 to 3). Initially, all contestants are at the start of the race track (position 0) and must race on a 20 meter track (positions numbered 0 to 19). Each participant has its own technique; some run fast, but are sometimes lazy; while others run slowly but steadily. All rabbits make 1 movement one after the other and the one who arrives at the end of the track before the others, wins the race. Here are the rabbit?s strategies :
At each turn, rabbit 0:
- sleeps (so does not run), 50% of the time;
- runs 4 meters, 30% of the time;
- runs 3 meters, 20% of the time.
At every turn, rabbit 1 runs 2 meters.
At each turn, rabbit 2:
- sleeps, 30% of the time;
- runs 3 meters, 70% of the time.
At each turn, rabbit 3:
- runs 1 meter, 80% of the time;
- runs 10 meters, 20% of the time.
The difficulty in the race is that the track has little slippery hills. So after each movement, rabbits can slide down a hill bringing them either closer to the finishing line, or closer to the starting line. How much they slide and in what direction depends on the slope of the hill at their current position, and how many meters they ran during this turn. Each position (or meter) of the hill has a slope represented by an integer between -3 and +2. If the slope is :
- zero : then, there is no hill at this position and rabbits that reach this position stay there.
- a negative integer : then, there is a declining side of a hill at this position, and all rabbits reaching this position will slide down
to a new position that is closer to the finishing line. The new position will be the current position minus the slope times the number of meters the rabbit ran.
For example, assume a rabbit was in position 10, then ran 5 meters to position 15. If the slope at position 15 is -2, then the new position of the rabbit will be 15 - (-2 x 5) = 25.
- a positive integer : then, there is a rising side of hill at that position, and all rabbits reaching this position will slide down to a new position that is closer to the starting line. The new position will be the current position minus the slope times the number of meters the rabbit ran.
For example, assume a rabbit was in position 10, then ran 5 meters to position 15. If the slope at position 15 is +1, then the new position of the rabbit will be 15 - (+1 x 5) = 10.
Notes on the race:
- Rabbits have 40 turns to reach the finish line. If after 40 turns no one has managed to reach position 19 (or beyond), then the race is cancelled and no winner is declared.
- A rabbit?s position can never go below 0. If, after calculating a rabbit?s position, you arrive at a negative position (ex. position -3), then consider that it is at position 0.
- Consider that any position outside the track (ex. position 0 or position 20) has a slope of 0.
- If a rabbit reaches position 19 (or goes beyond it), it does not immediately win the race. If any other rabbit reaches position 19 (or beyond) during the same turn, then there is a tie.
- If at the same turn, one rabbit reaches position 19, and another reaches a position higher than 19, the second rabbit does not win the race because it went further than the first. They both win.
Ok I know this is long and boring to read but I already completed the majority of the assignment here is my code:
public class Assignment_3 {
public static void main (String args[])
int[] position = new int[20];
int[] slope = new int[20];
int[] moveRabbit = new int[4];
moveRabbit[1] = 2;
int[] currentPosition = new int[4];
int currentPositionandSlope = 0;
for (int i=0;i<position.length;i++)
{ position=i;
System.out.print(position[i] + " ");
System.out.println();
for (int i=0;i<(position.length-5);i++)
{ slope[i]=(int) (-3 + Math.random()*5);
for (int i=0;i<position.length;i++)
System.out.print(slope[i] + " ");
System.out.println();
for (int turn=1;turn<=40;turn++)
int randomNb0 = (int) (Math.random () * 100);
int randomNb2 = (int) (Math.random () * 100);
int randomNb3 = (int) (Math.random () * 100);
if (randomNb0<=50)
moveRabbit[0] = 0;
else if (randomNb<=30)
moveRabbit[0] = 4;
else
moveRabbit[0] = 3;
if (randomNb2<=30)
moveRabbit[2] = 0;
else
moveRabbit[2] = 3;
if (randomNb3<=80)
moveRabbit[3] = 1;
else
moveRabbit[3] = 10;
for (int j=0;j<=3;j++)
System.out.println ("Rabbit" + j + " is at position " + position[currentPosition[j]]);
if (slope[currentPosition[j]+moveRabbit[i]] < 0)
currentPositionandSlope = position[currentPosition[j]+moveRabbit[j]] - (slope[currentPosition[j]+moveRabbit[j]] * moveRabbit[j]);
else if (slope[currentPosition[j]+moveRabbit[i]] > 0)
currentPositionandSlope = position[currentPosition[j]+moveRabbit[j]] - (slope[currentPosition[j]+moveRabbit[j]] * moveRabbit[j]);
else
currentPositionandSlope = (currentPosition[j]+moveRabbit[j]);
System.out.println ("it will move by " + moveRabbit[j] + ", but at position " + (position[currentPosition[j]] + moveRabbit[j]) + " there is a slope of " + slope[currentPosition[j] + moveRabbit[j]]);
System.out.println ("so it will slip by " + (position[currentPositionandSlope] - moveRabbit[j]) + " positions, and end up at position " + position[currentPositionandSlope]);
currentPosition[j] += currentPositionandSlope;
*Ok basically my question is that in the assignment there is an example output where the rabbit is at position 21 but the array is only 20 in length and my program crashes if i go beyond the array length.*
The example output is here:
Welcome to the 4 rabbit race:
position: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
slopes: 0 0 1 -2 1 0 -1 -1 1 -2 1 0 -1 -1 1 0 0 0 0 0
TURN #1
rabbit 0 is at position 0
it will move by 3, but at position 3 there is a slope of -2
so it will slip by 6 positions, and end up at position 9
rabbit 1 is at position 0
it will move by 2, but at position 2 there is a slope of 1
so it will slip by -2 positions, and end up at position 0
rabbit 2 is at position 0
it will move by 3, but at position 3 there is a slope of -2
so it will slip by 6 positions, and end up at position 9
rabbit 3 is at position 0
it will move by 1, but at position 1 there is a slope of 0
so it will slip by 0 positions, and end up at position 1
TURN #2
rabbit 0 is at position 9
it will move by 0, but at position 9 there is a slope of -2
so it will slip by 0 positions, and end up at position 9
rabbit 1 is at position 0
it will move by 2, but at position 2 there is a slope of 1
so it will slip by -2 positions, and end up at position 0
rabbit 2 is at position 9
it will move by 3, but at position 12 there is a slope of -1
so it will slip by 3 positions, and end up at position 15
rabbit 3 is at position 1
it will move by 1, but at position 2 there is a slope of 1
so it will slip by -1 positions, and end up at position 1
TURN #3
rabbit 0 is at position 9
it will move by 3, but at position 12 there is a slope of -1
so it will slip by 3 positions, and end up at position 15
rabbit 1 is at position 0
it will move by 2, but at position 2 there is a slope of 1
so it will slip by -2 positions, and end up at position 0
rabbit 2 is at position 15
it will move by 3, but at position 18 there is a slope of 0
so it will slip by 0 positions, and end up at position 18
rabbit 3 is at position 1
3
it will move by 10, but at position 11 there is a slope of 0
so it will slip by 0 positions, and end up at position 11
TURN #4
rabbit 0 is at position 15
it will move by 0, but at position 15 there is a slope of 0
so it will slip by 0 positions, and end up at position 15
rabbit 1 is at position 0
it will move by 2, but at position 2 there is a slope of 1
so it will slip by -2 positions, and end up at position 0
*rabbit 2 is at position 18*
*it will move by 3, but at position 21 there is a slope of 0*
*so it will slip by 0 positions, and end up at position 21*
*We have a potential winner...*
rabbit 3 is at position 11
it will move by 1, but at position 12 there is a slope of -1
so it will slip by 1 positions, and end up at position 13
So yeah :) that's basically my question (all this text for a simple question like that lol)
If you've managed to get to the end of my post then any guidance on my code would be appreciated too :)I'm not going to read that long post. As suggested, produce an SSCCE
and paste in the exact, complete error message, and indicate clearly which line causes it.
I did notice this though:
Ok basically my question is that in the assignment there is an example output where the rabbit
is at position 21 but the array is only 20 in length and my program crashes if i go beyond the array length.Either you're misunderstanding something, or the assignment has a typo. If you have an array of length 20, then the indices are 0..19.
Maybe the instructor is calling index 0 position 1--separating Java's array impelementation details from
colloquial 1-based counting, so that the rabbit starts at "position 1" (index 0) goes through "position 20"
(index 19), and when he's done, he's "at postion 21"--i.e., past the finish line, off the end of the course, etc.
This won't correspond to any index in the array, but can still be considered a logical position in the race. "Oh, he's
at position 21. He's done. There's nothing more to do with the array, as it has no slot corresponding to
this 'done' position."
That's pure speculation on my part. You'll have to ask your instructor or figure out for yourself what's going on. -
A very simple question..Very Urgent
HI,
I have a very simple question.I am able to set up the client authentication as well as server authentication. Now do i need to authenticate (both server as well as client auth.) for every request i send to the server on https...i think it should be like that it should authenticate only for the first time and for the next upcoming requests in same session should not require any server or client authentication.. i think as it happens in browsers..
what is the fact actually??..can somebody put some light...right now in my case it is authenticating for every requests..
This is what i have done..
/****constructor part********/
// and tm are arrays of keymanagers and trustmanagers for client keystore and truststore
sslContext.init(km, tm, null);
HttpsURLConnection.setDefaultSSLSocketFactory(ssf);
HttpsURLConnection.setDefaultHostnameVerifier(new MYHostNameVerifier());
/****Method to send the request and response*********/
urlConn = (HttpsURLConnection)url.openConnection();
urlConn.setDoInput(true);
urlConn.setDoOutput(true);
OutputStream os = urlConn.getOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
oos.writeObject(someobject);
oos.flush();
InputStream is1 = urlConn.getInputStream();
ObjectInputStream ois = new ObjectInputStream(is1);
SomeObject retObj = null;
retObj = (SomeObject)ois.readObject();
ois.close();
System.out.println("Get String>>>>> "+retObj.getString());
I am creating the object of this class..and calling the method again and again for sending requests and response..so i think handshake everytime i call the method...what i want is that handshake should happen for the first time and for the next requests no handshake or certificates should be checked or processed..
is it possible ..how..what i need to do for that..
please help me in this..
Akhil NagpalHi,
how could I achieve SSL Session Resumption using HttpsURLConnection.
Thanks. -
I think is a very simple question, I ve got a JComBox with an array of Strings. Something like this:
JPanel myPanel;
JComBox box;
String levels[]={"Level 1","Level 2","Level 3","Level 4","Level 5"};
box = new JComboBox (levels);
myPanel.add(box);
Ok. My question is: How can I let just the level 1 enable at first, or how can I enable or disable just one level of the JCombox, like level 1 and 2 enable but level 3, 4 and 5 disable.
Thanks a lot!! Hope someone helps me!!I don't think this is possible with a JComboBox. I believe it is with a JMenu and JMenuItems.
You could only display valid options by adding/deleting them. Or you could handle it in the listener code. ie if they select an invalid option do nothing. This would require you keeping track of which options are valid elsewhere in the code. -
Trying to teach self Java-question with arrays
I have a question with arrays. I have a simple inventory program that I am writing(very simple). I have declared and created my array. Is this the time I should build a new class outside of my main in order to hold my array? I am still trying to sort through classes and when to create them. My thought is that because it is a hierarchy I should have a new class. For example, Albums is at the top and then there are specific types of albums, like TributeAlbum, PremiereAlbum, etc. Do I need a class for each of these? When I create the class, do I use the same name as the array?
More info, just in case: My original class is AlbumInventory. I have created an array to hold 25 TributeAlbums which has 4 instance variables.
Question 2: Why can I not refer to an album variable like TributeAlbums[0].itemNumber?
Thanks in advance for your input.
DeniseI have a question with arrays. Okay.
I have a simple
inventory program that I am writing(very simple). I
have declared and created my array. Is this the time
I should build a new class outside of my main in
order to hold my array? In an OO language classes are usually a good idea.
I am still trying to sort
through classes and when to create them. My thought
is that because it is a hierarchy I should have a new
class.This sounds a bit confused. You should have a new class when it is appropriate to do so.
For example, Albums is at the top and then
there are specific types of albums, like
TributeAlbum, PremiereAlbum, etc. Do I need a class
for each of these? Not sure. Why is the type not an attribute of the Album class? This (attribute) seems at first glance to be the way to do it.
When I create the class, do I use
the same name as the array?
? I am going to say no but I'm not following what you are really asking here.
More info, just in case: My original class is
AlbumInventory. I have created an array to hold 25
TributeAlbums which has 4 instance variables.
Can you please post some of your actual formatted code? It would also be helpful to know what the attributes for an Album are as you have them. -
Simple question on the main method
Hello,
I have a very simple question and hope that somebody 'out there' can help me on this topic:
I just want to pass some Strings to the main method, which means that I want to do sth. like this:
java ProgramXY parameter1, parameter2
I thought it was possible to access these parameters in my main method like the following:
public static void main(String argv[]) {
System.out.println(argv[0]);
System.out.println(argv[1]);
But it does not work. So what do I do wrong ? Thank you for your help,
FindusThat should actually work - though you don't use the comma - just spaces. I don't think a comma would screw things up though - it would just become part of parameter 1.
Of course, you still want to check argv.length to make sure you don't try reading an array member that doesn't exist.
What are you seeing if you're not seeing your parameters?
If you're not putting enough parameters, it MIGHT be possible that you're getting an ArrayIndexOutOfBounds exception before the first System.out.println's are flushed to the screen - unsure though. -
Current Year and current month?simple question
How can i get four Digit current Year and two digit current month. So if is march it should get me as 03 and the Year as 2002. Please do help me, is a simple question isn't it ?. Thanks for your earliest response.
Thank you.i have a directory structre of the format
REPTS2000209/E200209-98000001
in which 2002 is current YEAR
09 is current month
and 9800001 is the code i would submit(list box) from a form
so what i need is a program that can generate the above path and open that particular PDF file
so basically E200209-98000001.pdf is the PDF file.
i am submitting it from JSP page. PLEASE HELP ME how can i program. -
This might be a simple question. On those sites that do not differentiate between CRT, laptop, tablet etc. such as an iPad Mini and using the Facebook site fir example when going to post a comment and you do not have a enter button on the IPad and the speed is slow how do you get your comments to post if we do not have a enter button?
<Email Edited By Host>I don't have facebook so I cannot answer but for your personal security, I have asked the hosts to remove your e-mail address. It is very unwise to publish this.
-
A simple question on random number generation?
Hi,
This is a rather simple question and shows my newbieness quite blatantly!
I'm trying to generate a random number in a part of a test I have.
So, I have a little method which looks like this:
public int getRandomNumber(int number){
Random random = new Random(number);
return random.nextInt(number);
}And in my code I do int random = getRandomNumber(blah)...where blah is always the same number.
My problem is it always returns the same number. What am I missing here. I was under the impression that nextint(int n) was supposed to generate the number randomly!! Obviously I'm doing something wrong or not using the correct thing. Someone please point out my stupidity and point me in the right direction? TaI think the idea is that Random will generate the same pseudo-random sequence over and over if you don't supply a seed value. (The better to debug with, my dear.) When you're ready to put an app into production, the seed value should be the current system time in milliseconds to guarantee a new sequence with each run.
Do indeed move Random outside the loop. Think of it like a number factory - instantiate it once and let it pump out the random values for you as needed. -
A simple Question about % in CR Chart!
Hi, I have another simple question.
When i use SQL to storage data and wanna Crystal Report to display the data in chart using %
which data type should i use?
float or string?
and I found when i use 0.12 as 12% in database , It could not display in Crystal Report line chart normally.
What should I do??
Please Help!!!
Thank you VERY MUCH!!!If you have the datatype as string from your database then try adding the string field as a summary field in chart and select maximum instead of count and if you have them in number format then you can directly select the percentage in chart.
Regards,
Raghavendra -
Simple question about generate proxy
Hi guys...
This is a simple but a truly simple question....
When trying to create a proxy from our messages interfaces using SPROXY, i'm not able to get the Software component versions that were used from the sld...
Do I have to export them? Or import them?Hi Goncalo,
Check if it helps...
Re: SW component version not visible in SPROXY
Regards
Anand -
Simple question: I want to use iCloud as a back up disk for my documents folder. How can I do this? If I cannot do this, why am I paying for access to "the cloud?"
iCloud does not provide general file storage or backup, so you cannot back up your Documents folder using it. You will need to find a third-party alternative - this page examines some options (some are free):
http://rfwilmut.net/missing3
iCloud at basic level, with 5GB is storage, is free: you only pay anything if you want to increase the storage space. -
Simple question about JAVA path
Hi. I have a simple question , but I spent several hours trying to find an answer.
How do I know the location of the java executable which is used by Concurrent Manager.
I already know that running which java under application user will not give me the correct answerMaybe you can try like this:
public String getPath(){
Class cls=getClass();
String className=cls.getName();
String packageName=cls.getPackage().getName();
System.out.println(className);
System.out.println(packageName);
String newClassName=className.replaceAll("\\.", "/");
String resouceName=newClassName+".class";
System.out.println(resouceName);
URL url;
url=cls.getClassLoader().getResource(resouceName);
String path="";
path=url.getFile();
return path;
}
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