Perl provides an alternative (?:. . . ) form of parentheses that supports grouping in regular expressions without performing capture. Using this syntax, Example 14.57 could have been written as follows:

What purpose does this extra notation serve? Why might the code here be preferable to that of Example 14.57?

Transcribed Image Text:

if (/^([+-]?) ((\d+)\.I(\d*)\. (\d+))(?:e([+-]?\d+))?$/) { # floating-point number print "sign: print "integer: ", $3, $4, "\n"; print "fraction: print "mantissa: " print "exponent: ", $6, "\n"; ", $1, "\n"; $5, "\n"; $2, "\n"; # not $7 %3D