Knowledge Quiz: Tutorial 1

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What is the key difference between a for loop and a while loop?

A for loop repeats a fixed number of times; a while loop repeats until a condition becomes false.Both loops behave the same; the difference is only stylistic.A for loop cannot modify objects outside the loop.A for loop checks its condition at the end of the loop.A for loop cannot be nested inside another loop.

• TRUE
• FALSE: Both loops have different behaviors and use cases.
• FALSE: a for loop can modify objects outside the loop.
• FALSE: a for loop checks its condition at the beginning of the loop.
• FALSE: a for loop can be nested inside another loop.

Which of the following is a vectorized operation in R?

for (i in 1:length(x)) y[i] <- x[i] + 1y <- paste(x)y <- x + 1lapply(x, function(i) i + 1)apply(x, 1, sum)

• FALSE: This is a for loop, not vectorized.
• TRUE: paste is vectorized and can operate on each element of x.
• TRUE: This is a vectorized operation; R adds 1 to each element of x simultaneously.
• TRUE: lapply applies the function to each element of x, which is a form of vectorization.
• TRUE: apply applies the sum function across rows of x, which is vectorized.

What is missing in the following R code so that the loop returns these values?

{. .cell-code} for (i in 1:10) { __________________ a <- i^2 print(a) }

[1] 1
[1] 4
[1] 9
[1] 16
[1] 36
[1] 49
[1] 64
[1] 81
[1] 100

To skip the iteration when i is equal to 5, you need to add a conditional statement that checks for this condition and uses the next function to skip to the next iteration of the loop. The missing line is: if (i == 5) next.