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### Re^3: Numification of strings

by ww (Archbishop)
 on Aug 02, 2010 at 12:33 UTC ( #852462=note: print w/replies, xml ) Need Help??

in reply to Re^2: Numification of strings

"but it's only about converting undef"

Lest you or anyone else read that as generally true, I repeat, for emphasis re warnings (or for brevity here, -w) and re 'consistent':

```perl -we "\$x="LanX"; print (\$x * 3);"
Argument "LanX" isn't numeric in multiplication (*) at -e line 1.
0
perl -we "\$x="LanX"; print (\$x % 3);"
Argument "LanX" isn't numeric in modulus (%) at -e line 1.
0
perl -we "\$x="LanX"; print (3^\$x);"
Argument "LanX" isn't numeric in bitwise xor (^) at -e line 1.
3
perl -we "\$x="LanX"; print (3**\$x);"
Argument "LanX" isn't numeric in exponentiation (**) at -e line 1.
1

but

```perl -we "\$x='7LanX'; print (3^\$x);"
Argument "7LanX" isn't numeric in bitwise xor (^) at -e line 1.
4
perl -we "\$x='7LanX'; print (\$x*3);"
Argument "7LanX" isn't numeric in multiplication (*) at -e line 1.
21
perl -we "\$x='7LanX'; print (3**\$x);"
Argument "7LanX" isn't numeric in exponentiation (**) at -e line 1.
2187

and where it's useful -- using a string as a number because it's being used in an operation which is arithmetic:

```perl -we "\$x=\"5\"; print (\$x*3);"  # 2
15
perl -we "\$x='5'; print (\$x*3);"
15

2   Interesting (or not enough coffee yet?): doze balked at doublequotes without escapes here, but passed 'em cheerfully above. WTF?

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Re^4: Numification of strings
by LanX (Bishop) on Aug 02, 2010 at 12:52 UTC
> > "but it's only about converting undef"

converting undef is differently handled with ++, enabling warnings doesn't help here!

Cheers Rolf

More like "doesn't hurt".
```++\$count{\$_} for @list;
would have to be written
```\$count{\$_} = \$count{\$_}//0 + 1 for @list;

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