In the previous lesson we learned how to define and "call" a re-usable module of code, i.e., a function. Sometimes when we call a function (tell RoboBlocky to execute the code inside the function), it is useful to send additional information to the function. For example, the createSquare function in the previous lesson had the robot draw squares with side length 6. But it would make the function even more useful if we could send it any side length we wanted, rather than it just being fixed at 6.

To do this, we can create functions with input values. In programming terminology, these input values are called "parameters" or "arguments", and we talk about "passing a parameter" or "passing an argument" to the function. In other words, we send ("pass") an input value to the function for it to use when its code is executed.

We add input values to a RoboBlocky function by clicking on the small gear wheel icon in the function block, as shown below:

The example code below shows how it works.