# The {tab} Operator

Several question types use the {tab} operator to specify answer key behaviors.

## Behaviors

The {tab} operator is used in Answer to define answer key behaviors for several question types.

Question Type Behavior
Matching Separates the first-column entry from the matching second-column entry.
Numerical Separates the answer key from an optional numerical tolerance for the question part.

## Adding the {tab} Operator

To add the {tab} operator, either type the characters {tab} or click Add tab.You cannot enter {tab} by pressing the Tab key. You can also abbreviate {tab} as {}.

Note You cannot enter {tab} by pressing the Tab key.

## Representing the {tab} Operator in Perl Strings Used in Answer

From time to time, you might want to include the {tab} operator in a Perl string — usually defined in Question — that you will use in Answer to specify an answer key. This is usually the case for Fill-in-the-Blank questions for which the number of alternative answers might vary.

Inserting the characters {tab} in a Perl string will not add the {tab} operator when the string is used in Answer. Instead, you must use one of two approaches:

• Specify the {tab} operator literally in Answer. You can define multiple variables for the alternative answer keys and separate them with literal {tab} operators. Any null answer keys are ignored.
• Specify the {tab} operator using the characters \t in a double-quoted Perl string that is used in Answer.
Note This method might not work for chemPad or Marvin JS questions.