For example, with 2-D array X, and 4 points:
n = 4;
X = rand(n, 2);
allDistances = pdist2(X(1, :), X)
allDistances = pdist2(X(2, :), X)
allDistances = pdist2(X(3, :), X)
you get
allDistances =
0 0.137705462706709 0.300486552306604 0.770204210452277
allDistances =
0.137705462706709 0 0.176471014289295 0.648765114726253
allDistances =
0.300486552306604 0.176471014289295 0 0.596340359329654
Adapt as needed for other n.