R Repeat Loop

A repeat loop just repeats a block of code indefinitely.

In this loop, no condition checking is performed in order to end the loop.

To stop repeating the loop, you must put a condition explicitly inside it with break statement. Failing to do so will create an infinite/endless loop.

Syntax

Here’s the syntax of the repeat loop:

r repeat loop syntax

Examples

A repeat loop without a break statement results into an infinite/endless loop.

Example: Infinte loop with repeat

> repeat {
+   print("Press Esc to stop me!")
+ }
[1] "Press Esc to stop me!"
[1] "Press Esc to stop me!"
...
...

However, you can put a condition explicitly inside the body of the loop and use the break statement to exit the loop.

Example: Iterate until x becomes 5

> x <- 1
> repeat {
+   print(x)
+   if (x > 4)
+     break
+   x <- x + 1
+ }
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5