A for loop is used to iterate over a vector in R programming.

## Syntax of for loop

```
for (val in sequence)
{
statement
}
```

Here, `sequence`

is a vector and `val`

takes on each of
its value during the loop. In each iteration, `statement`

is
evaluated.

## Flowchart of for loop

## Example: for loop

Below is an example to count the number of even numbers in a vector.

```
x <- c(2,5,3,9,8,11,6)
count <- 0
for (val in x) {
if(val %% 2 == 0) count = count+1
}
print(count)
```

**Output**

[1] 3

In the above example, the loop iterates 7 times as the vector
`x`

has 7 elements.

In each iteration, `val`

takes on the value of corresponding
element of `x`

.

We have used a counter to count the number of even numbers in `x`

.
We can see that `x`

contains 3 even numbers.

Check out these examples to learn more about for loop: