Name Rules for Variables and Devices in VEXcode IQ – VEX Library

In VEXcode IQ, you are required to give a name to a new variable when you create one. You also have the option to change a device’s name in the Robot Configuration.

Valid Name Rules

Variable names must be unique, but there are other specifications that the name must follow.

Variable names are used in the following places:

Device (created using Robot Configuration)
Numeric (created using “Make variable”)
Boolean (created using “Make a boolean”)
List (created using “Make a List”)
2D List (created using “Make a 2D List”)

Here is an overview of the criteria when choosing a valid name:

Example of an invalid variable name. The name reads 'bigNumber!', which includes an exclamation mark. A warning reads Symbols not allowed.

The name cannot use special characters.

Example of an invalid variable name. The name reads '2ndWheel', which begins with a number. A warning reads Letter required.

The name has to begin with a letter. It cannot start with a number.

Example of an invalid variable name. The name reads 'previous number', which includes a space. A warning reads No spaces allowed.

The name cannot use spaces.

Example of an invalid variable name. The name reads 'if', which is a word that VEXcode is already using. A warning reads VEXcode keyword not allowed.

The name cannot be a reserved word in VEXcode. A reserved word is a word or name that VEXcode is already using.

Examples: vex, Brain, time, for, while, break, else, not.

Example of an invalid variable name. The name reads 'counter', which is already defined in the project. A warning reads Name taken.

The name has to be unique (only used once), but you can have different cases (one uppercase and one lowercase).

Possible Name Errors

Example of a user creating a variable with a name that is already taken by another variable. A warning reads Name taken.

When you create a variable name, if you see a “Name Taken” error, it means there is a duplicate name in any of the groups above.

VEXcode IQ error prompt that reads Failed to Compile, Duplicate variable names found. The prompt lists two variables that are named myVariable and awesomeVar, and it lists both of their types as Number Variable and Boolean Variable.

You may encounter a case when opening a project made in an earlier version of VEXcode IQ that has a duplicate variable name. This will cause an error when compiling and you will see the error message:

The error message to the left shows the following problems:

The name “myvariable” was found as a numeric variable and a boolean variable.
The name “awesomeVar” was found as a numeric variable and a boolean variable.

To resolve the error, one of the duplicates will need to be removed or changed so they are unique.