$_ = 'abc';
print /(.)/g ? $1 : '[]', "\n";  # a
print /(.)/g ? $1 : '[]', "\n";  # b
print /(.)/g ? $1 : '[]', "\n";  # c
print /(.)/g ? $1 : '[]', "\n";  # []
print /(.)/g ? $1 : '[]', "\n";  # a