# Building Expressions

The first step in using the Expression Builder is to build an expression in the Build Expression pane.

To build an expression:

1. Hover the mouse cursor over the element that you want to add to your expression (expressions usually start with an **Input Column**) and click the arrow that appears to its right.
2. Add **Operators** additional **Input Columns** and **Functions** as required.

Information note

To add operators to your expression, you can use the **Operator** tab on the left or the **Operator** buttons located above the **Build Expression** pane or any combination of these.

**Example:**

To create an expression that combines the `FirstName` name and `LastName` columns, do the following:

1. Add the `FirstName` **Input Column** to the **Build Expression** pane.

2. In the **Operator** toolbar above the **Build Expression** pane, click the concatenate operator.

3. Then add a space between single quote characters and click the concatenate (`+`) operator again.

4. Add the `LastName` **Input Column** to the **Build Expression** pane.

   The expression would look like this:

![](https://help.qlik.com/en-US/compose/December2024/Content/Resources/Images/ComposeForDataLakes/expression_example.png)