Converting a string to an already defined variable name in R -

i new r. looking write query, example

hello_world<- c(1,2,3,4) hi_world <- c(5,6,7)  x<- c(paste("hello","world",sep="_"),paste("hi","world",sep="_"))

i have stored defined variable names string inside variable x

now x, how can call out of 2 variables displays

5 6 7

if call x[2] hi_world?

swift