How does Integer.toString in Java exactly work?

Question

public static void main (String[] args) { 
    int a = 0010;
    String num = Integer.toString(a);
    System.out.println(num);    
}

Why does it print 8 not 0010?

Many variations on this question here on SO - see eg http://stackoverflow.com/questions/24031843/is-00-an-integer-or-octal-in-java/24032020#24032020 — fvu, Dec 18 '14 at 19:23
possible duplicate of [Integer with leading zeroes](http://stackoverflow.com/questions/565634/integer-with-leading-zeroes) — fvu, Dec 18 '14 at 19:24

score 3 · Accepted Answer · answered Dec 18 '14 at 19:21

3

Java interprets integers that start with 0 as being expressed in octal. 10 in octal (base 8) is 8 in decimal (base 10). Integer.toString() is doing the correct thing in this case, because the value of a is indeed 8.

answered Dec 18 '14 at 19:21

Gian

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score 1 · Answer 2 · answered Dec 18 '14 at 19:23

1

Integers are stored in binary form in memory. There are several ways to define integer literal. 0010 is octal, in base 8. toString prints in base 10 (decimal).

answered Dec 18 '14 at 19:23

Andrey

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How does Integer.toString in Java exactly work?

2 Answers2