q=74894
str_extract(q,'[0-9]{1}')
#?str_extract for more details
#在1到80里随机抽取100个数,可重复
x
<-
sample(1:80,
100,
replace
=
T)
#
unique(x)把x中出现过的元素提取出来,
length()看看有多少个
length(unique(x))
[1]
52
q=74894
str_extract(q,'[0-9]{1}')
#?str_extract for more details
#在1到80里随机抽取100个数,可重复
x
<-
sample(1:80,
100,
replace
=
T)
#
unique(x)把x中出现过的元素提取出来,
length()看看有多少个
length(unique(x))
[1]
52