Hi All,
I find some difference in auto increment operator precedence between C and Perl. As almost say that for Perl, the operators derived from C has the same precedence, this is somewhat different.
Here is the sample code:
Perl:
#!/usr/local/bin/perl -W
$i = 2;
$j = 10;
$k = $i++ - $i++;
print $k,"\n";
$i = 2;
$j = 10;
$k = ++$i - ++$i;
print $k,"\n";
$i = 2;
$j = 10;
$k = $i++ + $i++;
print $k,"\n";
$i = 2;
$j = 10;
$k = ++$i + ++$i;
print $k,"\n";
which outputs:
-1
0
5
8
and the equivalent C program:
#include <stdio.h>
main()
{
int i,j,k;
i = 2;
j = 10;
k = i++ - i++;
printf("i=%d, j = %d, k = %d\n",i,j,k);
i = 2;
j = 10;
k = ++i - ++i;
printf("i=%d, j = %d, k = %d\n",i,j,k);
i = 2;
j = 10;
k = i++ + i++;
printf("i=%d, j = %d, k = %d\n",i,j,k);
i = 2;
j = 10;
k = ++i + ++i;
printf("i=%d, j = %d, k = %d\n",i,j,k);
}
which outputs:
k = 0
k = 0
k = 4
k = 8
as you can observe the difference in outputs.
Could anyone help me explaining whats happening here .
why is the output different different especially with post-increment operator?
Thanks,
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
| |
For: |
|
Use: |
| & | | & |
| < | | < |
| > | | > |
| [ | | [ |
| ] | | ] |
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.