Control Structures - CodeToLive

Control Structures in R

Control structures in R allow you to control the flow of your program. They include conditional statements (if-else, ifelse) and loops (for, while, repeat).

If-Else Statements

The if-else statement is used to execute a block of code based on a condition.


age <- 20
if (age >= 18) {
    print("You are an adult.")
} else {
    print("You are a minor.")
}

Ifelse Function

The ifelse function is a vectorized version of the if-else statement.


ages <- c(15, 20, 25)
status <- ifelse(ages >= 18, "Adult", "Minor")
print(status)

Loops

Loops are used to execute a block of code repeatedly. R supports for, while, and repeat loops.


# For Loop
for (i in 1:5) {
    print(i)
}

# While Loop
count <- 0
while (count < 5) {
    print(count)
    count <- count + 1
}

# Repeat Loop
count <- 0
repeat {
    print(count)
    count <- count + 1
    if (count >= 5) {
        break
    }
}

Break and Next Statements

The break statement exits the loop, while the next statement skips the current iteration.


# Break Example
for (i in 1:10) {
    if (i == 5) {
        break
    }
    print(i)
}

# Next Example
for (i in 1:10) {
    if (i %% 2 == 0) {
        next
    }
    print(i)
}

Vectorized Operations

R supports vectorized operations, which allow you to perform operations on entire vectors without explicit loops.


# Vectorized Addition
v1 <- c(1, 2, 3)
v2 <- c(4, 5, 6)
result <- v1 + v2
print(result)

Next: Functions