mget vs get unable to understand the difference

I am little confused with the way the mget and get works

I am using the lapply to read the multiple dataframes (df1, df2) and do the manipulation, however when i use the get the object is read but if i replace it with mget, it does not work, not sure why

what i noticed is that if i use the get the dataframe is searched in the global environment and read as a dataframe, however if I use mget then the object is read as a list due to which the further code does not work

df1 <- tribble(
~City_Name,  ~Temp,  ~Pres,  ~Wind_Hor, ~Wind_Ver,  ~S_Moist,  ~Temp1, ~Pres1,  ~Wind1,  ~S_Moist1,
'Mi',  27,  1019,  287,  278,  78,  1,  2,  2,  1,
'Mi',  28,  1019,  289,  277,  78,  2,  2,  1,  3
)

df2 <- tribble(
  ~City_Name,  ~Temp,  ~Pres,  ~Wind_Hor, ~Rainf,  ~S_Moist,  ~Temp1, ~Pres1,  ~Wind1,  ~S_Moist1,
  'Mi',  27,  1019,  287,  278,  78,  1,  2,  2,  1,
  'Mi',  28,  1019,  289,  277,  78,  2,  2,  1,  3
)

dfs1 <- c('df1','df2')

var <- c('City_Name',  'Temp',  'Pres' , 'Wind_Hor' , 'Wind_Ver' , 'Rainf' , 'S_Moist')

lapply(dfs1, \(x) {
  dfn <- mget(x, envir = .GlobalEnv, inherits = T)
  dfn[[var[which(is.na(match(var,names(dfn))))]]] <- NA
  dfn <- dfn %>% select(all_of(var))
  return(assign(x,dfn,envir = .GlobalEnv))
})

get is used to find only one variable and return the value stored in the variable, while mget finds multiple variable and returns them in a list. What you are trying to do can be simplified as

lapply(mget(dfs1), \(x) `[<-`(x, setdiff(var, names(x)), value = NA)[var]) |>
   list2env(.GlobalEnv)


df1
# A tibble: 2 × 7
  City_Name  Temp  Pres Wind_Hor Wind_Ver Rainf S_Moist
  <chr>     <dbl> <dbl>    <dbl>    <dbl> <lgl>   <dbl>
1 Mi           27  1019      287      278 NA         78
2 Mi           28  1019      289      277 NA         78

df2
# A tibble: 2 × 7
  City_Name  Temp  Pres Wind_Hor Wind_Ver Rainf S_Moist
  <chr>     <dbl> <dbl>    <dbl> <lgl>    <dbl>   <dbl>
1 Mi           27  1019      287 NA         278      78
2 Mi           28  1019      289 NA         277      78

Here is a solution with mget.
From the help page ?get:

> Search by name for an object (get) or zero or more objects (mget).

And in section Value:

> For get, the object found. If no object is found an error results.
>
> For mget, a named list of objects (found or specified via ifnotfound).

suppressPackageStartupMessages(
  library(tibble)
)

df1 <- tribble(
  ~City_Name,  ~Temp,  ~Pres,  ~Wind_Hor, ~Wind_Ver,  ~S_Moist,  ~Temp1, ~Pres1,  ~Wind1,  ~S_Moist1,
  'Mi',  27,  1019,  287,  278,  78,  1,  2,  2,  1,
  'Mi',  28,  1019,  289,  277,  78,  2,  2,  1,  3
)

df2 <- tribble(
  ~City_Name,  ~Temp,  ~Pres,  ~Wind_Hor, ~Rainf,  ~S_Moist,  ~Temp1, ~Pres1,  ~Wind1,  ~S_Moist1,
  'Mi',  27,  1019,  287,  278,  78,  1,  2,  2,  1,
  'Mi',  28,  1019,  289,  277,  78,  2,  2,  1,  3
)

dfs1 <- c('df1','df2')

var <- c('City_Name',  'Temp',  'Pres' , 'Wind_Hor' , 'Wind_Ver' , 'Rainf' , 'S_Moist')

# get all data sets in one call to mget
df_list <- mget(dfs1, envir = .GlobalEnv, inherits = TRUE)
lapply(df_list, \(x) {
  icol <- var[!var %in% names(x)]
  x[icol] <- NA
  x[var]
}) |>
  list2env(envir = .GlobalEnv)
#> <environment: R_GlobalEnv>

df1
#> # A tibble: 2 × 7
#>   City_Name  Temp  Pres Wind_Hor Wind_Ver Rainf S_Moist
#>   <chr>     <dbl> <dbl>    <dbl>    <dbl> <lgl>   <dbl>
#> 1 Mi           27  1019      287      278 NA         78
#> 2 Mi           28  1019      289      277 NA         78

df2
#> # A tibble: 2 × 7
#>   City_Name  Temp  Pres Wind_Hor Wind_Ver Rainf S_Moist
#>   <chr>     <dbl> <dbl>    <dbl> <lgl>    <dbl>   <dbl>
#> 1 Mi           27  1019      287 NA         278      78
#> 2 Mi           28  1019      289 NA         277      78

^{Created on 2023-07-17 with reprex v2.0.2}