Conditional sapply in R

I am trying to apply conditional sapply to vectors as shown below
Basically, then the vector contains "input_" in the beginning, then apply some condition to LHS and RHS.

The condition is when there is "input_b", then RHS should be paste0(x, "d"), where LHS should be gsub("input_", "", x). Here RHS is working fine but not the LHS part. Refer expected output below

exp <- c("a", "input_b")
asd <- as.list(sapply(exp , function(x) {ifelse(substr(x, start = 0, stop = 5) == "input", assign(gsub("input_", "", x), paste0(x, "d")), assign(x, x))}))
asd
$a
[1] "a"

$input_b
[1] "input_bd"

Expected output

asd
$a
[1] "a"

$b
[1] "input_bd"

>Solution :

Use setNames instead of assign (sapply seems redundant, because exp is not a list):

exp_values <- ifelse(startsWith(exp, "input"),
                     paste0(exp, "d"),
                     exp)

exp_names <- ifelse(startsWith(exp, "input"),
                    gsub("input_", "", exp),
                    exp)

as.list(setNames(exp_values, exp_names))

Output:

$a
[1] "a"

$b
[1] "input_bd"

It is however still not clear to me what problem we’re solving exactly, so it might not be the most efficient way to solve the problem at hand.