Why 0010 give different result in array in java

Question

If I placed 00 or 0 before digits values in array output become different.

 int arr[][]=new int[3][2];
    arr[0][0]=00;
    arr[0][1]=01;
    arr[1][0]=10;
    arr[1][1]=0011;
    arr[2][0]=0020;
    arr[2][1]=21;
    for(int a[]: arr){
        for(int c : a){
            System.out.println(c);
        }

    }

Output is : 0 1 10 9 16 21

@RohitJain it looks like he may have been expecting `0, 1, 10, 11, 20, 21` — CubeJockey, Apr 17 '15 at 13:53
By putting a leading zero in front of the numbers you're turning them into **octal** literals. — JonK, Apr 17 '15 at 13:53
I guess the OP's question is *why the input and output are different. Who is converting the octal numbers to decimal ?*. So, not sure if this should be marked as a duplicate. Re-opened it! — TheLostMind, Apr 17 '15 at 13:58

OldCurmudgeon · Accepted Answer · 2015-04-17T14:04:56.217

15

A number with a leading zero is treated as Octal.

Your 0011 is octal 8 + 1 = 9, 0020 is 2 * 8 = 16.

Note that your 00 and 01 are also being interpreted in Octal but they just happen to be the same value as their decimal counterparts.

edited Apr 17 '15 at 14:04

answered Apr 17 '15 at 13:53

OldCurmudgeon

64,482
16
119
213

score 6 · Answer 2 · answered Apr 17 '15 at 13:53

6

Because you are inserting numbers in base-8 (octal) format (use of 0 at the beginning) and printing them using base-10 (decimal) using Integer.toString(i, 10);

println() converts all integers to base-10 and prints them.

answered Apr 17 '15 at 13:53

TheLostMind

35,966
12
68
104

Integer.toString(i, 10); only convert single index in array. how can i conver whole array(2-diementional) – Syeda Shah Apr 17 '15 at 14:09
@SyedaShah- You will have to call it on each element of 2-D array. No other option :) – TheLostMind Apr 17 '15 at 14:10

score 5 · Answer 3 · answered Apr 17 '15 at 13:56

There is a literal prefix 0 which means octal number

int decimal = 100; // 100 represented in decimal base int octal = 0144; // decimal 100 represented in octal base int hex = 0x64; // decimal 100 represented in hexadecimal base int bin = 0b1100100; // decimal 100 represented in binary base

Why 0010 give different result in array in java

3 Answers3

Related