How is the R repeat Loop different from the while Loop?

a) The repeat loop does not check a condition before each iteration, while the while loop does

b) The repeat loop is only used for infinite loops

c) The repeat loop is faster than the while loop

d) The repeat loop can only iterate over numeric values

Answer:

a) The repeat loop does not check a condition before each iteration, while the while loop does

Explanation:

The repeat loop in R differs from the while loop in that it does not check a condition before each iteration. Instead, it continues indefinitely until a break statement is encountered. In contrast, the while loop evaluates a condition before each iteration and only continues if the condition is TRUE.

# repeat loop example
i <- 1
repeat {
    print(i)
    i <- i + 1
    if (i > 3) {
        break
    }
}

# while loop example
i <- 1
while (i <= 3) {
    print(i)
    i <- i + 1
}

# Output for both:
# [1] 1
# [1] 2
# [1] 3

In both loops, the output is similar, but the mechanism differs. The repeat loop relies on the programmer to include a break statement to exit the loop, while the while loop automatically stops when the condition is no longer TRUE.