tidbitR - %in% and %notin%

emp <- data.frame(
  name = c("ram", "prabhu", "tina", "venkatesan"),
  dept = c("IT", "HR", "compliance", "operations")
)
emp

##         name       dept
## 1        ram         IT
## 2     prabhu         HR
## 3       tina compliance
## 4 venkatesan operations

retired <- data.frame(name = c("tina",
                               "prasath"))
retired

##      name
## 1    tina
## 2 prasath

emp$name %in% retired$name

## [1] FALSE FALSE  TRUE FALSE

which(emp$name %in% retired$name)

## [1] 3

emp[emp$name %in% retired$name, ]

##   name       dept
## 3 tina compliance

tryCatch(
  {
    emp[emp$name %notin% retired$name, ] #such an operator does not exist
  }, error = function(e) {
    paste(e, "is handled.")
  }
)

## [1] "Error in `[.data.frame`(emp, emp$name %notin% retired$name, ): could not find function \"%notin%\"\n is handled."

`%notin%` <- #create a new binary pipe operator
  function (x, table)
    is.na(match(x, table, nomatch = NA_integer_))

emp[emp$name %notin% retired$name, ]

##         name       dept
## 1        ram         IT
## 2     prabhu         HR
## 4 venkatesan operations