String array to integer

Question

I have a text file with the name of "w1_slave" as follows:

3c 00 4b 46 ff ff 0d 10 16 : crc=16 YES

3c 00 4b 46 ff ff 0d 10 16 t=29937

From the above, I only need to extract the integer number 29937, and my code is:

public static void main(String[] args) throws IOException {
    // create token1
    String token1 = "";

    // create Scanner inFile1
    @SuppressWarnings("resource")
    // detect delimiter "," and " "
    Scanner w1Slave = new Scanner(new File("C:/Users/Hamid/Desktop/w1_slave.txt")).useDelimiter(",| ");

    List<String> temps = new ArrayList<String>();

    // while loop
    while (w1Slave.hasNext()) {
      // find next line
      token1 = w1Slave.next();
      temps.add(token1);
    }
    w1Slave.close();

    String[] tempsArray = temps.toArray(new String[0]);
    int tempsArrayLength = tempsArray.length - 1;
    System.out.println(tempsArray[tempsArrayLength]);

The output is t=29937. Could you tell me how I can extract just 29937 as an integer or double number, please?

Glorfindel · Accepted Answer · 2015-07-16 12:17:51Z

5

The easiest way would be to add = as a delimiter - replace

.useDelimiter(",| ");

with

.useDelimiter(",|= ");

To convert it to a double, use

double value = 0;
try {
    value = Double.parseDouble(temps.get(temps.size() - 1));
} catch (NumberFormatException e) {
    // not a number - do something
}

You don't need to convert the list to an array - you can delete this part of your code:

String[] tempsArray = temps.toArray(new String[0]);
int tempsArrayLength = tempsArray.length - 1;
System.out.println(tempsArray[tempsArrayLength]);

edited Jul 16, 2015 at 12:17

answered Jul 15, 2015 at 20:58

Glorfindel

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3 Comments

Hamid Malmir Over a year ago

Thank you so much. The delimiter works, but the conversion does not work. it returns 0 instead of 29937.

Glorfindel Over a year ago

That's because your conversion from List to array is not correct, and unnecessary. I've updated my answer.

Hamid Malmir Over a year ago

Thanks. It works, but with double not with integer. so I change the codes.

Daniel Burgner · Accepted Answer · 2015-07-15 21:12:38Z

1

My suggestion would be to use the substring function.

String strNumber = tempsArray[tempsArrayLength].substring(2);

Then use parseInt to get the integer value.

int nNumber = Integer.parseInt(strNumber);

answered Jul 15, 2015 at 21:12

Daniel Burgner

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Comments

Pankaj Verma · Accepted Answer · 2015-07-16 12:06:26Z

You was very near to your code. i think you need to modify your code like this

public static void main(String[] args) throws IOException {
        // create token1
        String token1 = "";

        // create Scanner inFile1
        @SuppressWarnings("resource")
        // detect delimiter "," and " "
        Scanner w1Slave = new Scanner(new File(C:/Users/Hamid/Desktop/w1_slave.txt")).useDelimiter(",| ");

        List<String> temps = new ArrayList<String>();

        // while loop
        while (w1Slave.hasNext()) {
          // find next line
          token1 = w1Slave.next();
          temps.add(token1);
        }
        w1Slave.close();

        String[] tempsArray = temps.toArray(new String[0]);
        int tempsArrayLength = tempsArray.length - 1;
        String str[]=tempsArray[tempsArrayLength].split("=");
        // System.out.println(tempsArray[tempsArrayLength]);
        int i=Integer.parseInt(str[1]);
        System.out.println(i);

}

Denis Lukenich · Accepted Answer · 2015-07-15 20:59:45Z

0

Use the parseInt or parseDouble functions:

int number = Integer.parseInt(tempsArray[tempsArrayLength]);

or

double number = Double.parseDouble(tempsArray[tempsArrayLength]);

answered Jul 15, 2015 at 20:59

Denis Lukenich

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