You can pass multiple strings, which are all checked. If any of them is undefined, the function returns TRUE

isUndefined(s, ..., verbose = TRUE)

Arguments

s

A string to be checked for NA/NULL

...

More strings to be checked

verbose

If TRUE and 's' is NULL/NA, will print the name of the variable which was passed in

Examples

isUndefined(NA)       ## TRUE
#> Warning: Variable 'NA' is NA/NULL!
#> [1] TRUE
isUndefined(NULL)     ## TRUE
#> Warning: Variable 'NULL' is NA/NULL!
#> [1] TRUE
isUndefined(NA, NULL) ## TRUE
#> Warning: Variable 'NA' is NA/NULL!
#> Warning: Variable 'NULL' is NA/NULL!
#> [1] TRUE
isUndefined("")       ## FALSE
#> [1] FALSE
isUndefined("", NA)   ## TRUE
#> Warning: Variable 'NA' is NA/NULL!
#> [1] TRUE
isUndefined(NA, "")   ## TRUE
#> Warning: Variable 'NA' is NA/NULL!
#> [1] TRUE
isUndefined(1)        ## FALSE
#> [1] FALSE
myVar = NA
isUndefined(myVar)    ## TRUE, with warning "Variable 'myVar' is NA/NULL!"
#> Warning: Variable 'myVar' is NA/NULL!
#> [1] TRUE