string - Treat a Character as a variable -

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suppose have following code

a<-c(1,2,3) b<-'a'

now treat string in 'b' variable 'a' when input function or operation. imagine "treat.as.variable()" real function this:

treat.as.variable(b)+c(1,2,4) [1] 2 4 7

is there function this, predefined? or way in general?

use get function

> get(b) + c(1,2,4) [1] 2 4 7

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