Variables

This article shows you how to use the Variable blocks in our Dynamic Engine.

What Is a Variable?

The term variable is the same term used in mathematics or computer science. It is a named value that can be changed - aka it "varies".

The Variable Blocks

There are three kinds of variable blocks that you can use:

1. Set

2. Get

3. Change

Variable: Set

The set block assigns a value to a variable, creating the variable if it doesn't already exist. For example, this sets the value of the variable named "age" to the number "18".

Variable: Get

The get block provides the value of a variable. Continuing from the previous example, it would get the number "18".

Without a corresponding set block, the engine does not know what you want to do with the number "18". Think of it like a floating puzzle piece that needs to be connected to something. Without a connection, it's just floating around the office looking for a fresh cup of coffee (like our hipster UX designer).

Variable: Change

The change block adds a number to a variable. Continuing from the previous example, this would add the number "1" to the number "18".

The change block broken down into a calculation would look like this:

This is the equivalent of saying set the variable age to it's previous number (ie. 18) plus the number 1. So think of change like a shortcut.

Variable: Menu

Click on the variable's dropdown symbol (light blue triangle) to get the following menu:

The menu provides the following options:

• Existing variables: The names of all existing variables defined in the program. In this example, we only have one variable (age).

• Rename variable...: Change the name of the selected variable. Selecting this option opens a prompt to enter a new name.

• Delete the 'selected' variable: Deletes all blocks that reference this variable wherever it appears in the program.

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Example Question

Consider the following multiple-choice question. The goal of this question is to add randomness to the "too young" and "too old" distractors.

Here is what the Dynamic Engine would look like:

Age is being set to make the correct answer "18" and the other answer options set to Math blocks that randomly choose numbers in a range.

Here is what a sample question would look like (values highlighted in blue for convenience):