To check which element of a list which is a logical list is TRUE, we can follow the below steps −
Let’s create a list as shown below −
List<- list(TRUE,FALSE,TRUE,TRUE,FALSE,FALSE,FALSE,TRUE,FALSE,TRUE,FALSE,FALSE,TRUE,TRUE,TRUE,TRUE,FALSE,TRUE,FALSE,FALSE,TRUE,FALSE,TRUE,FALSE,TRUE) List
On executing, the above script generates the below output(this output will vary on your system due to randomization) −
[[1]] [1] TRUE [[2]] [1] FALSE [[3]] [1] TRUE [[4]] [1] TRUE [[5]] [1] FALSE [[6]] [1] FALSE [[7]] [1] FALSE [[8]] [1] TRUE [[9]] [1] FALSE [[10]] [1] TRUE [[11]] [1] FALSE [[12]] [1] FALSE [[13]] [1] TRUE [[14]] [1] TRUE [[15]] [1] TRUE [[16]] [1] TRUE [[17]] [1] FALSE [[18]] [1] TRUE [[19]] [1] FALSE [[20]] [1] FALSE [[21]] [1] TRUE [[22]] [1] FALSE [[23]] [1] TRUE [[24]] [1] FALSE [[25]] [1] TRUE
Unlist of the List elements and use which function to find which elements are TRUE in List −
List<- list(TRUE,FALSE,TRUE,TRUE,FALSE,FALSE,FALSE,TRUE,FALSE,TRUE,FALSE,FALSE,TRUE,TRUE,TRUE,TRUE,FALSE,TRUE,FALSE,FALSE,TRUE,FALSE,TRUE,FALSE,TRUE) < which(unlist(List))
[1] 1 3 4 8 10 13 14 15 16 18 21 23 25