##assign a value to a name
var = 'test1'
assign('var_name1', var)
var_name1

assign_global_var <- function(){
  assign('var_name', var)
  assign('global_var', var, envir = .GlobalEnv) ##global
  
  var1 <- 'var1'
  var1_global <<- 'var1_global' ##global
}
assign_global_var()
var_name ##not found
global_var
var1 ##not found
var1_global