However it doesn't matter, because the '= 0' doesn't actually add anything.

From testing, it seems to matter on the Mac platform including CentOS 7.3. I compared the output with this site. No warnings are emitted on CentOS 7.3.

Without '= 0'

predigit, nines = 0;

-- Mac OS X, Apple LLVM version 7.3.0 (clang-703.0.31)

demo.c:41:13: warning: expression result unused [-Wunused-value]
            predigit, nines = 0;
            ^~~~~~~~
1 warning generated.

0314159265358979323846264338327954288419716939937510582097494459230781
+6406286208998628734825342117067
                                 |                                    
+                |
                                 4                                    
+                7

-- Linux, gcc version 4.8.5 20150623

0314159265358979323846264338327954288419716939937510582097494459230781
+6406286208998628734825342117067
                                 |                                    
+                |
                                 4                                    
+                7

[download]

With '= 0'

predigit = 0, nines = 0;

0314159265358979323846264338327950288419716939937510582097494459230781
+6406286208998628034825342117067
                                 |                                    
+                |
                                 0                                    
+                0

[download]

In reply to Re^4: porting C code to Perl by marioroy
in thread porting C code to Perl by Discipulus

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.