Question

How to get number of digits from an int in Java

Answer 1

package javaapplication1;
 
public class Example {
    public static void main(String[] args) {
        
        int n = 78910;
        int count_digits = (int)(Math.log10(n) + 1); // for n > 0
        
	    System.out.format("count_digits = %d\n", count_digits);
    }
}
 
 
/*
run:
  
count_digits = 5
  
*/

 

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Answer 2

package javaapplication1;
 
public class Example {
    public static void main(String[] args) {
        
        int n = 78910;
        int count_digits = String.valueOf(n).length();
        
	    System.out.format("count_digits = %d\n", count_digits);
    }
}
 
 
/*
run:
  
count_digits = 5
  
*/

 

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Answer 3

package javaapplication1;
 
public class Example {
    public static void main(String[] args) {
        
        int n = 78910;
        int digits = count_digits(n);
        
	    System.out.format("digits_count = %d\n", digits);
    }
    
    static int count_digits(int n)
    {
	    int i;
 	    n = Math.abs(n);
	    for (i = 0; n > 0; i++)
		    n /= 10;
	    return i;			
    }
}
 
 
/*
run:
  
digits_count = 5
  
*/

 

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