  Nuclear charge radii of $^{7,9,10,11}$Be have been determined by
high-precision laser spectroscopy. On-line measurements were performed with
collinear laser spectroscopy in the $2s_{1/2} \to 2p_{1/2}$ transition on a
beam of Be$^{+}$ ions. Collinear and anticollinear laser beams were used
simultaneously and the absolute frequency determination using a frequency comb
yielded an accuracy in the isotope-shift measurements of about
  1 MHz. Combination with accurate calculations of the mass-dependent isotope
shifts yield nuclear charge radii. The charge radius decreases from $^7$Be to
$^{10}$Be and then increases for the halo nucleus $^{11}$Be. When comparing our
results with predictions of {\it ab initio} nuclear structure calculations we
find good agreement. Additionally, the nuclear magnetic moment of $^7$Be was
determined to be $-1.3995(5)\mu_{\rm N}$ and that of $^{11}$Be from a previous
$\beta$-NMR measurement was confirmed.
