Thread: checking for digit while reading from a file

guys, let's say I have a file that contains

1
33
b s
4
10
f
a
120
5 6

I want to count the numbers and letters, in my code I'm using the Character.isDigit(String.chartat(0)) to identify the numbers. But you can only use nextInt(); to read the input. this is very straight forward using next(), but how could I do it using nextInt();

public static void main(String[] args) {
        mixedF();
    }
 
    public static void mixedF() {
        int numbers = 0; 
        int words = 0;
        String ch;      
        try {
            Scanner in = new Scanner(new File("myFile.txt"));
            while(in.hasNext()) {
                ch = in.next();
                if(Character.isDigit(ch.charAt(0)))
                    numbers++;
                else
                    words++;              
            }
 
            System.out.println("numbrers: "+numbers);
            System.out.println("words: "+words);
        }
        catch (FileNotFoundException ex) { ex.getMessage(); }
 
    }

I would suggest you read about the scanner class and become familiar with the methods available and their usage. Reading that page will answer your question and perhaps teach you even more useful things.

nextInt() will give you an error once it encounters a letter... how would you handle that?

Originally Posted by Norm

put the call to nextInt() inside of a try catch block to catch the error of trying to read a non-integer.

this is my implementation, but I'm getting "imputMisMatchException"

public static void mixedF() {
        int numbers = 0; 
        int words = 0;
        int num;      
        try {
            Scanner in = new Scanner(new File("myFile.txt"));
            while(in.hasNext()) {
                try {
                    num = in.nextInt();
                    numbers++; 
                }
                catch (Error e) { words++; }              
 
                }            
 
 
            System.out.println("numbrers: "+numbers);
            System.out.println("words: "+words);
        }

Exception in thread "main" java.util.InputMismatchException