# Variable$update

### Variable$<mark style="color:purple;">update</mark>(*\*, label=NULL, description=NULL, value\_labels=NULL*) → self

Update metadata attributes on a variable. Only updates an attribute if the value is not NULL; to unset an attribute, set it to an empty string.

### **Parameters:**

**`label` :&#x20;*****str, default NULL*** \
If specified, will set the variable's label. Must be less than or equal to 256 characters. Pass an empty string to unset a variable's label.

**`description` :&#x20;*****str, default NULL***\
If specified, will set the variable's description. Must be less than or equal to 5000 characters. Pass an empty string to unset a variable's description.

**`value_labels` :&#x20;*****list<{ "value": str, "label": str }>*****&#x20;|&#x20;*****NULL, default NULL***\
If specified, will set the value labels on a variable. Passed as a list of named lists with attributes "value" and "label". Pass an empty list to unset the variable's value labels.

### **Returns:**&#x20;

**self (a** [**Variable**](https://docs.redivis.com/api/client-libraries/redivis-r/reference/variable)**)**

### **Examples:**

```r
table <- redivis$organization("Demo")$dataset("iris_species")$table("iris")

variable <- table$variable("sepalLengthCm")
variable$update(label="Sepal length in centimeters",
                description="A detailed description of how this variable was collected"
                )
         
# Update value labels on another variable (this particular example is a bit contrived)
table$variable("Species")$update(list(
    list(value="Iris-setosa", label="A detailed description about this value"),
    list(value="Iris-versicolor", label="A detailed description about this other value"),
))
```