Please show what you have tried so far:

use strict;
use warnings;

my $string ="GAP_SPAN09 - GAP SPAN base (Scratch Testing [TSMC11] : ts
+mc11_wld(sxfatd12j)) GAP_SPAN03 - GAP SPAN base (DFD E2E Testing [TSP
+AN04: tspan04-dfdint-wld(sxfamd6f)) POS_WLI02 - POS_WLI02 Web Logic I
+ntegrator";

my @array;
while ($string =~ m/(\w+\s?)-/g)
{
    push (@array, $1);
}


print join("\t", @array);
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Your array has only one element. I think meant a string as input! Must have book for Regex challenges: Mastering Regular Expressions UPDATE: Other monks have already posted answers while I was drafting this!