  Distribution of loops in a one-dimensional random walk (RW), or,
equivalently, neutral segments in a sequence of positive and negative charges
is important for understanding the low energy states of randomly charged
polymers. We investigate numerically and analytically loops in several types of
RWs, including RWs with continuous step-length distribution. We show that for
long walks the probability density of the longest loop becomes independent of
the details of the walks and definition of the loops. We investigate crossovers
and convergence of probability densities to the limiting behavior, and obtain
some of the analytical properties of the universal probability density.
