In R, NA denotes ‘Missing Values’ or ‘Not Available’. To remove NA values from a vector, you can use the `na.rm()` or `is.na()` functions. Additionally, R provides various other methods to eliminate NA values from a vector.

When you perform an arithmetic operation on an R vector containing NA values, the result will be NA. Generally, any operation involving NA results in NA. Therefore, it is advisable to clean the vector by removing all NA values before performing arithmetic operations.

Alternatively, you can also replace NA with 0 before applying any arithmetic or statistical operations.

## 1. Quick Examples of Remove NA from Vector

Following are quick examples of how to remove NA values from R Vector.

``````
# Quick Examples

# Create Vector
ids <- c(10,5,NA,15,10)

# Using is.na()
x <- ids[!is.na(ids)]

# Using na.rm=TRUE
x <- max(ids, na.rm=TRUE)

# Using na.omit()
x <- na.omit(ids)

# Remove NA from string Vector.
states = c('NY','DC',NA,'CA','NV',NA)
x <- na.omit(states)

# Using exclude
x <- na.exclude(states)
print(x)
``````

## 2. Remove NA from Vector using is.na()

The `is.na()` indicates which elements are missing. The `is.na(x)` function returns a logical vector of the same size as `x` with value `TRUE` when the corresponding element in `x` is `NA`.

### 2.1 is.na() Syntax

The following is the syntax of the is.na() function.

``````
# Syntax
vector[!is.na(vector)]
``````

### 2.2 Remove NA from Vector Example

`is.na()` function is used to remove NA values from the vector. This function returns a vector consisting of logical values (i.e. TRUE or FALSE), whereby TRUE indicates a missing value.

``````
# Using is.na()
ids <- c(10,5,NA,15,10)
is.na(ids)

# Output
# [1] FALSE FALSE  TRUE FALSE FALSE
``````

By negating the result you will get a logical vector with FALSE at the position of NA value. Now use this result on vector bracket notation to remove elements at the FALSE position this ideally removes NA values from the vector.

``````
# Remove NA values from Vector
x <- ids[!is.na(ids)]
print(x)

# Output
# [1] 10  5 15 10
``````

## 3. Using na.rm=TRUE

When used `na.rm=TRUE` with any arithmetic or statistical functions it removes the `NA` values from vector while performing operations. By default `FALSE` is set to `na.rm`.

Following is the syntax of the `na.rm=TRUE` and its usage with `max()` function.

``````
# Syntax of na.rm=TRUE
max(vector, na.rm = TRUE)
``````

Lets use this and calculate sum(), max() and mean() for the Vector. If you don’t remove the NA values from the vector, then all these operations returns NA as a result.

``````
# Using na.rm=TRUE
x <- sum(ids, na.rm=TRUE)
print(x)

x <- max(ids)
print(x)

x <- mean(ids, na.rm=TRUE)
print(x)
``````

## 4. Remove NA from Vector using na.omit()

### 4.1 Syntax of na.omit()

Following is the syntax of the na.omit() function.

``````
# Syntax of na.omit()
na.omit(vector)
``````

### 4.2 Delete NA values from Vector

The following R program removes all NA values from the vector.

``````
# Using na.omit()
x <- na.omit(ids)
print(x)
``````

Yields below output

``````
# Output
[1] 10  5 15 10
attr(,"na.action")
[1] 3
attr(,"class")
[1] "omit"
``````

## 5. Remove NA from Vector using na.exclude()

### 5.1 Syntax of na.exclude()

Following is the syntax of the na.exclude() function.

``````
# Syntax of na.exclude()
na.exclude(vector)
``````

### 5.2 Drop NA Values from Vector

The following R program removes all NA values from the vector.

``````
# Using exclude
states = c('NY','DC',NA,'CA','NV',NA)
x <- na.exclude(states)
print(x)
``````

Usage and example of na.exclude() function.

``````
# Output
[1] "NY" "DC" "CA" "NV"
attr(,"na.action")
[1] 3 6
attr(,"class")
[1] "exclude"
``````

## Conclusion

In this article, you have learned the syntax of is.na(), na.omit() and na.exclude() and how to use these to remove NA values from the vector. You can find the complete example from this article at Github R Programming Examples Project.