How to check multiple values using if condition [duplicate]

Answer 1

In most cases, life is easier and lines are shorter without ifelse:

# short version
df$Status <- df$Remarks %in% c("ABC","AAB","ABB")  

This version is OK for most purposes but it has shortcomings. Status will be FALSE if Remarks is NA or, say "garbage" but one might want it to be NA in these cases and FALSE only if Remarks %in% c("XYZ", "ZZX"). So one can add and multiply the conditions and finally convert it to logical:

df$Status <- as.logical(with(df,
                  Remarks %in% c("ABC","AAB","ABB")  +
                  ! Remarks %in% c("XYZ","ZZX") ))

And the summary table with base R:

aggregate(df[,-(1:2)], df["ID"], function(x) if(is.numeric(x)) sum(x) else table(x))

Umm... perhaps some formatting would be useful:

t1 <- aggregate(df[,-(1:2)], df["ID"], function(x) if(is.numeric(x)) sum(x) else table(x))
t1 <- t1[, c(1,3,2)]
colnames(t1) <- c("ID", "", "Sum")
t1
#   ID FALSE TRUE Sum
# 1  1     1    2  37
# 2  2     1    1  26