R Programming language - R while Loop
In R programming language, the while
loop is used to repeat a block of code as long as a certain condition is met. The general syntax of a while
loop in R is as follows:
while (condition) { # code to execute while condition is TRUE }
The condition
is a Boolean expression that is evaluated before each iteration of the loop. If the condition is TRUE, the code inside the loop is executed; otherwise, the loop is exited.
Here is an example of a while
loop in R:
x <- 1 while (x <= 5) { print(x) x <- x + 1 }
In this example, the condition
is x <= 5
. The loop will continue to execute as long as x
is less than or equal to 5. Inside the loop, the value of x
is printed, and then incremented by 1. The output of this code will be:
[1] 1 [1] 2 [1] 3 [1] 4 [1] 5
Note that if the condition
is never met, the loop will never execute. Also, if the condition
is never false, the loop will run indefinitely, leading to an infinite loop. To avoid this, you should always make sure that the condition is eventually false.
You can also use break
statement inside a while
loop to break out of the loop prematurely. The break
statement is used to immediately exit the loop, regardless of the value of the condition. Here is an example:
x <- 1 while (TRUE) { print(x) x <- x + 1 if (x > 5) { break } }
In this example, the while
loop has a TRUE
condition, which means that it will execute indefinitely. However, the if
statement inside the loop checks if x
is greater than 5, and if so, executes the break
statement, which immediately exits the loop. The output of this code will be the same as the previous example.