Dynamic Variables in R - r

Question

I am using RStudio (ver. 3.0.2) and new to R.
In my task, would like to create the below variables in RScript and assign a value.
AA_1_11 <- 1
AA_2_22 <- 2
AA_3_33 <- 3
AA_4_44 <- 4
BB_1_11 <- 5
BB_2_22 <- 6
BB_3_33 <- 7
BB_4_44 <- 8
Rather to statically create the 8 lines above. I am intending to dynamically code those so that the codes are useful when the variables expand in future i.e AA,BB, could later extend to CC, DD etc.
Tried the below code:
char_list <- c("AA", "BB")
num_list <- c("1_11", "2_22", "3_33", "4_44")
i=1
char_num_array <-vector()
for (char in char_list) {
for (num in num_list) {
char_num_array[i] <- paste(char,num, sep = '_')
i <- i + 1
}
}
(char_num_array)
for (j in 1:length(char_num_array)){
char_num_array[j] <- j
}
Though I can create all the variables names as a string name, have no idea why the actual variables are not created in RStudio as shown in the picture below.
Hope you can guide me on this.
Update:
Thanks to all for your help. I really wanted to make separate variables so I can monitor the changes in the values on RStudio as the variables will continually be used for other manipulations i.e fitting, refitting etc.
Thanks to JDB. I have modified the codes to below, where i could be replaced with other mathematical equation.
char_list <- c("AA", "BB")
num_list <- c("1_11", "2_22", "3_33", "4_44")
i <- 1
for (char in char_list) {
for (num in num_list) {
assign(paste(char,num, sep = '_'), i)
i <- i + 1
}
}

Answer 1

You don't need a loop for this. The preferred "R way" to do this type of operation is to keep all these variables in a list. Along with keeping the global environment "clean", this makes it easier to refer to the variables, and also makes it easier to perform operations on them all at once later.
For example, for this operation you can do
char_list <- c("AA", "BB")
num_list <- c("1_11", "2_22", "3_33", "4_44")
x <- setNames(
as.list(1:8),
paste(rep(char_list, each=4), num_list, sep="_")
)
Now the variables you want are all stored in x
names(x)
# [1] "AA_1_11" "AA_2_22" "AA_3_33" "AA_4_44" "BB_1_11"
# [6] "BB_2_22" "BB_3_33" "BB_4_44"
and can be accessed by name with $, by name or number with [ and [[, with with(), etc...
x$AA_1_11
# [1] 1
x[[5]]
# [1] 5
with(x, c(AA_1_11, BB_4_44))
# [1] 1 8

Answer 2

There's no point in your code where you're telling R to create those variables. Your first loop DOES succeed in creating a vector list (a string) of the names you desire, but it's not assigning them any values as variables.
R is pretty good at dynamic variable creation, however. Why do you want to assign the same value to a bunch of different variables? Could you create a data frame, for example, with these variables?
array <- data.frame(variables = numeric(length(char_num_array)))
rownames(array) <- char_num_array
array
variables
AA_2_22 0
AA_3_33 0
AA_4_44 0
BB_1_11 0
BB_2_22 0
BB_3_33 0
BB_4_44 0
If you really want to create these as separate variables, you can use assign():
for(item in char_num_array) assign(item, 1)