Error with converting String array into int array

Question

a little help here. I'm so confused and have done so many variations of converting String array into int array.

I get numbers from a file then tokenize it. However, I get a NumberFormatException and a lot of errors when trying to convert the array. Any idea?

Here's my code below:

int[] intarray=new int[token.length];
    int i=0;
    for (String str : token){
        intarray[i++] = Integer.parseInt(str);
    }

Any help would be much appreciated.

[EDIT] When I do this code below. No errors but it only prints some integers in the token.

int[] ints = new int[arrays.length];
for(int i=0; i<array.length; i++){
  try{
    ints[i] = Integer.parseInt(array[i]);
  }
  catch(NumberFormatException nfe){
    //Not an integer, do some
  }
}

Here's the txt file where I get the numbers:

[SOLVED] I got it. Simply split("\W+"). I thought splitting " " is enough to also split newline. Thanks guys.

The problem is not in the code you posted, you need to post the code you're using to populate your tokens — morgano
– morgano, Commented Jan 29, 2014 at 6:50

Maroun · Accepted Answer · 2014-01-29 06:49:53Z

2

Probably str doesn't represent an int. See the docs - ... NumberFormatException - if the string does not contain a parsable integer.

To know your problem, you can do the following:

int[] intarray=new int[token.length];
int i=0;
for(String str : token){
   try {
       intarray[i++] = Integer.parseInt(str);
   } catch(NumberFormatException e) {
       System.out.println(str + " is not a parsable int");
     }
}

answered Jan 29, 2014 at 6:49

Maroun

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2 Comments

ThisGuy Over a year ago

` is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int is not a parsable int`

Maroun Over a year ago

Then you have this amount of unparsable ints. They are probably some empty Strings.

Baby · Accepted Answer · 2014-01-29 07:06:12Z

2

The best way is to make sure your str represent ints only, by removing all non-digit character:

for (String str : token){
    if(str.replaceAll("\\D","").length()>0)
        intarray[i++] = Integer.parseInt(str.replaceAll("\\D",""));
}

By the way, if white-spaces is the only possible non-digit characters to exist in your array, you can simply use str.trim()

edited Jan 29, 2014 at 7:06

answered Jan 29, 2014 at 6:50

Baby

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2 Comments

Njol Over a year ago

This can still result in a NumberFormatException if the value is too large for an int.

Baby Over a year ago

I assume there is no big number, referring to the sample above

Deepak Sharma · Accepted Answer · 2014-01-29 06:56:40Z

0

Hi i am fully agreed with @maroun but if you say you are passing only numeric value in token array then use the trim because sometime we do not take care of space before and after..

like if you try to convert

" 123 " to int it will throw error because of extra space

so i will suggest you to also use the trim() when u are parsing the string to int

intarray[i++] = Integer.parseInt(str.trim());

answered Jan 29, 2014 at 6:56

Deepak Sharma

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Comments

Madhura · Accepted Answer · 2014-01-29 06:56:41Z

0

You can get a NumberFormatException if you are reading even the spaces from your input. Please make sure that you trim your string before Integer.parseInt also check whether the string represents an integer

answered Jan 29, 2014 at 6:56

Madhura

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Comments

bhavesh kaila · Accepted Answer · 2014-01-29 06:59:13Z

0

I face the same problem but in my case string contains only number.and if your token contains only number value then you can try with

int[] intarray=new int[token.length];

int i=0;

for (String str : token) {

intarray[i++] = Integer.valueOf(str);

}

answered Jan 29, 2014 at 6:59

bhavesh kaila

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2 Comments

Deepak Sharma Over a year ago

i dont think replacing parseInt by valueOf will resolve the issue.. read it again

gowtham Over a year ago

Integer.valueOf(str) internally calls Integer.parseInt(str)

morgano · Accepted Answer · 2014-01-29 07:09:45Z

The problem is in the way you're getting the strings from your file. Try this function to get your array of strings:

String[] getTokens(String filename) {

    try {
        String line;
        StringBuilder fileInAStringBuilder = new StringBuilder();
        BufferedReader fileReader = new BufferedReader(new FileReader(filename));
        while((line = fileReader.readLine()) != null) {
            fileInAStringBuilder.append(line).append(' ');
        }
        String fileInAString = fileInAStringBuilder.toString();
        fileInAString = fileInAString.replaceAll("\\D", " ");

        fileReader.close();

        return fileInAString.split(" +");

    } catch (IOException e) {
        throw new RuntimeException(e);
    }

}

Your code would be something like this:

String[] token = getTokens("myFileName.txt");

int[] intarray=new int[token.length];
int i=0;
for (String str : token){
    intarray[i++] = Integer.parseInt(str);
}

Be also aware that this could fail if any of numbers is too big to "fit" in an int.

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