# Managing Variables

> In Studio, variables are used to store multiple types of data. Another key aspect of variables is that their value can change so that you can, for example, control how many times the body of a loop is executed.

In Studio, variables are used to store multiple types of data. Another key aspect of variables is that their value can change so that you can, for example, control how many times the body of a loop is executed.

:::note
* Variables need to be created with different
names, even if used in different scopes. If two variables share the same name but are in different scopes, the variable in the inner scope takes precedence. You can check out our [Workflow Design Naming Conventions](https://docs.uipath.com/studio/standalone/latest/user-guide/workflow-design#naming-conventions) recommendations.
* Variable names must start with a letter or underscore `_`.
* Using certain keywords (for example, "Replace") to name variables may cause
unexpected errors.
:::

From Studio's perspective, the variable's name is its unique ID and it defines the way it’s being displayed and used. If that changes or gets deleted, Studio is not able to interpret the `.xaml` files based on the loaded activities. All strings have to be placed between quotation marks.

:::important
If there are both a **variable** and an [argument](https://docs.uipath.com/studio/standalone/latest/user-guide/managing-arguments#managing-arguments) with the same name, the variable is always defaulted to and used at runtime.
:::

You can manage variables in multiple ways. To benefit from the best experience and flexibility, we recommend using the [Data Manager](https://docs.uipath.com/studio/standalone/latest/user-guide/using-the-data-manager).

## Variable Type

The data stored within a variable is called a value, and it can be of multiple types. When you create a variable. the following options are available:

* **Boolean** - This type has only two possible values: `true` or `false`. These variables enable you to make decisions, and therefore have a better control over your workflow.
* **Int32** - This type is used to store numeric information. Some of its uses are to perform equations, comparisons and pass important data.
* **String** - Stores text information. This type of variable can be used to store any text-based information such as employee names, usernames or any other strings.
* **Object** - Can be used to store different types of data. You can use this type of variable in situations where you need flexibility for the type of data you store in a variable. Make sure that the data type used in Object variables is compatible with the activities that use the variable.
* **System.Data.DataTable** - This type can store big pieces of information, and act as a database or a simple spreadsheet with rows and columns. Can be useful to migrate specific data from a database to another and extract information from a website and store it locally in a spreadsheet, among other uses.
* **Array of [T]** - Enables you to store multiple values of the same type.
* **Create type from JSON schema** - Allows you to generate a new type from a JSON schema, making it easier to interact with APIs, complex objects, or Agents. Selecting this option opens a window where you can give your type a name and write or paste your JSON schema.
* **Browse for Types** - Allows you to [explore more types](https://docs.uipath.com/studio/standalone/latest/user-guide/managing-variables#managing-variables) that can be relevant to your task.
  :::note
  Using variables of types defined by the language used in the project as static results in a compilation error in Windows and cross-platform projects.
  :::

## Variable Scope

The scope property gives variables a well-defined context in which they can be used. The scope can be set to global (available in the entire project), the current workflow file, or any container activity within the workflow file.

You can only create global variables from the Data Manager.

:::note
* Global variables are not serializable, and therefore incompatible with
long-running persistence activities.
* Global variables are not
supported in library projects.
* In C# projects, using a global variable or a global constant in activities
requires following the format: `GlobalVariablesNamespace.GlobalVariables.YOUR_GLOBAL_VARIABLE_NAME`. In VB projects, you can reference the global variable or global constant by its name directly.
:::

## Creating Variables

### From the Data Manager

  ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-613117-0b1fdcdf.webp)

1. Open the Data Manager.
2. Navigate to the **Variables** panel.
3. Select the **Create variable** line. A new variable is created.
4. Configure the name, data type, scope, and default value for the variable.

The default type of variables created this way is **String**.

### From the Body of an Activity

   ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-169121-a966a775.webp)

1. From the **Activities** panel, drag an activity to the **Designer** panel. Either right-click a field and select **Create Variable** from the context menu, press Ctrl+K, or select **Create Variable** from the **Plus** ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-plus_menu-8a20ac7d.png) menu on the right side of the field. The **Set Var** field is displayed.
2. Fill in the name and press Enter. The variable is created and visible in the field. Check its scope and type in the **Data Manager**.

#### From Expressions

Alternatively, variables can be created from expressions directly in an activity input field or the **Expression Editor**:

1. Select a part of the expression and press Ctrl+K. The **Set Var** field is displayed.
2. Fill in the name and press Enter. The variable is created. Check its scope and type in the **Data Manager**.

   ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-171320-52c61178.gif)

Variables created in these two ways automatically receive the type according to the activity. For example, if you create a variable in the `Data Table` field of a [Write Range](https://docs.uipath.com/activities/docs/write-range) activity, the variable's type is set to `DataTable`. If you create a variable in the `Text` field of a [Write Line](https://docs.uipath.com/activities/docs/write-line) activity, the variable's type is set to `String`.

The scope of such variables is the smallest container it is part of. The type is automatically generated depending on the selected property.

### From the Properties Panel

   ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-168225-edc3ac7a.webp)

1. In the **Properties** panel of any activity, either right-click a field and select **Create Variable** from the context menu, press Ctrl+K, or select **Create Variable** from the **Plus** ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-plus_menu-8a20ac7d.png) menu on the right side of the field. The **Set Var** field is displayed.
2. Fill in the name and press Enter. The variable is created and visible in the field. Check its scope and type in the **Data Manager**.

The scope of variables created in this way is the smallest container it is part of. The type is automatically generated depending on the selected property.

### Variables automatically generated from activity outputs (for Windows and cross-platform projects only)

If the **Auto-generate Activity Outputs** design setting is enabled, Studio automatically populates each **Output** field of activities that generate an output with a variable. You can then use the generated variable in other activities by selecting the **Plus** ![](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-plus_menu-8a20ac7d.png) menu on the right side of the activity input fields and then **Use Variable**.

If you prefer to manually create an output variable, you can do so inside the output field. This will replace the generated variable with the variable that you created. If you select the **Clear value** option after manually creating a variable, the default generated variable is restored.

The generated variable is available in the **Variables** panel in the **Data Manager** (if the variable is used in another activity). As with any other variable, you can change the generated variable’s name, data type, scope, and default value.

The scope of the generated variable is based on the activity’s location in the workflow (for example, the scope is different if the activity is in the main sequence or inside a **For each** activity). The scope of the generated variable updates if you copy, cut, or paste the activity. Renaming an activity does not impact the generated variable. Deleting an activity, however:

* Clears the value of the variable if the variable is not used.
* Deletes the variable if the variable is used and a warning is displayed in the activities that used the variable as an input.

## Removing Variables

You can remove variables from the Data Manager:

1. Open the Data Manager.
2. Navigate to the **Variables** panel.
3. Right-click a variable, and then select **Delete Variable**. Alternatively, select it and press the Delete key.

### Removing All Unused Variables

To remove all the variables that are defined but not used anywhere in the current file, select **Remove Unused** > **Variables** in the Studio ribbon, and then select **Yes** when prompted for confirmation. This also removes variables that are unused but mentioned in annotations.

:::note
If you remove or upgrade a package that may lead to a variable or argument being undefined, an **Unknown Type** is added in its place so that the file can be opened and edited in Studio.
:::

## Browsing for .Net Variable Types

To search for types of variables that are not displayed by default in the **Variable Type** list, do the following:

1. In the **Data Manager**, from the **Data Type** dropdown for a variable, select **Browse for Types**. You can also access the menu from the **Variable Type** dropdown in the Variables panel. The **Browse and Select a .Net Type** window is displayed.
2. In the **Type Name** field, type a keyword for the variable you are looking for, such as excel. Note that the result section is updated, displaying all the .Net variable types that contain your keyword.
3. Select one and click **OK**. A new variable is created with the selected type and is displayed in the **Variables** panel.

   ![docs image](https://dev-assets.cms.uipath.com/assets/images/studio/studio-docs-image-167161-ff503b7b.webp)

   :::note
   After first using a type of variable from the **Browse and Select a .Net Type** window, it is displayed in the **Variable Type** drop-down list, in the **Variables** panel.
   :::

Variable and argument types part of assemblies proprietary to Studio or Robot are hidden. Workflows that reference types from such assemblies should not be affected at runtime. To use a type from a non-.Net framework assembly, add it as a dependency to your project with the help of the [Manage Packages](https://docs.uipath.com/studio/standalone/latest/user-guide/managing-dependencies#managing-dependencies) window.

:::note
Assigning a floating point number literal (for example, 10.5) to a variable or an argument of type float (`System.Single`) results in a compilation error when running the workflow. To successfully assign the value, you can either:
* Use the `f` or `F` suffix (`1.5f` or
`1.5F`)
* Use cast operators (`(float)1.5` for C# or `CSng(1.5)` for
VB)
:::