R Misc Operators

Beyond arithmetic, comparison, logical, and assignment operators, R provides several miscellaneous operators that appear frequently in real code. These handle sequences, membership tests, and pipe operations.

The Colon Operator : (Sequence Generator)

1:10        # 1 2 3 4 5 6 7 8 9 10
5:1         # 5 4 3 2 1  (descending)
-3:3        # -3 -2 -1 0 1 2 3

The colon operator generates integer sequences. It is one of the most used operators in R — especially in for loops and vector indexing.

for (i in 1:5) {
  cat(i, "")
}
# 1 2 3 4 5

The %in% Operator (Membership Test)

"mango" %in% c("apple", "mango", "banana")   # TRUE
"grape" %in% c("apple", "mango", "banana")   # FALSE

# Works on vectors too
fruits <- c("kiwi", "mango", "peach", "fig")
fruits %in% c("mango", "fig")
# [1] FALSE TRUE FALSE TRUE

The %% and %/% Operators (Arithmetic)

17 %% 5    # 2  (remainder)
17 %/% 5   # 3  (quotient, whole part only)

These appeared in arithmetic operators but qualify as miscellaneous because of their %..% syntax, which is how R marks infix operators.

The Pipe Operator |> (Native, R 4.1+)

The pipe passes the result of one expression as the first argument to the next function. Think of it as "then do this".

# Without pipe
result <- round(sqrt(mean(c(4, 9, 16, 25))), 2)

# With native pipe |>
result <- c(4, 9, 16, 25) |> mean() |> sqrt() |> round(2)

print(result)   # 3.54

Flow diagram with pipe:
c(4,9,16,25) ──|>──> mean() ──|>──> sqrt() ──|>──> round(2)
     ↓               ↓              ↓               ↓
  vector           13.5           3.67...          3.67

The Magrittr Pipe %>% (dplyr/tidyverse)

Before R 4.1 introduced |>, the %>% pipe from the magrittr package was standard. Both work similarly. The magrittr pipe is still widely used in dplyr code.

library(magrittr)
c(1, 4, 9, 16) %>% sqrt() %>% sum()   # 10

The %o% and %x% Operators

# Outer product
1:3 %o% 1:3
#     [,1] [,2] [,3]
# [1,]  1    2    3
# [2,]  2    4    6
# [3,]  3    6    9

# Kronecker product (advanced matrix operation)
matrix(1:4, 2, 2) %x% matrix(1:4, 2, 2)

Creating Custom Infix Operators

R lets you define your own operators using the %name% pattern:

# Custom operator: concatenate strings without spaces
`%++%` <- function(a, b) paste0(a, b)

"Hello" %++% "World"   # "HelloWorld"
"ID" %++% 42           # "ID42"

Summary of Miscellaneous Operators

Operator   Type                    Example
──────────────────────────────────────────────────────
:          Sequence                1:10
%in%       Membership test         "a" %in% c("a","b")
%%         Modulo                  10 %% 3 = 1
%/%        Integer division        10 %/% 3 = 3
|>         Native pipe             x |> mean()
%>%        Magrittr pipe           x %>% mean()
%o%        Outer product           1:3 %o% 1:3
%x%        Kronecker product       M1 %x% M2

The sequence operator and %in% appear in almost every R script. The pipe operators become essential once you start working with data manipulation packages like dplyr. These tools make R code shorter, more readable, and easier to follow.