lapply(x, runif)

[[1]]

[1] 0.7567216

[[2]]

[1] 0.6671460 0.5853487

[[3]]

[1] 0.6894451 0.6012011 0.4198921

[[4]]

[1] 0.3292182 0.9232095 0.7794852 0.3744533

> lapply(x, runif, min=0, max=100)

[[1]]

[1] 13.2469

[[2]]

[1] 41.00204 41.69753

[[3]]

[1]? 0.4434934 46.4495736 13.3511447

[[4]]

[1] 30.59451 56.64134 42.04451 22.90153