Macros Overview

Macros are built-in functions that handle common operations in question writing — math formatting, string manipulation, array processing, conditional logic, and feedback generation.

Macro Categories

Category	Purpose	Key Functions
Math	Numeric computations, formatting	numfmt(), fracsimp(), gcd(), lcm()
String	Text processing and formatting	strtoupper(), trim(), str_replace()
Array	Array creation and manipulation	array(), sort(), array_sum()
Format	Display formatting	displaynum(), fracformat(), sciformat()
Conditional	Branching and logic	if/else, isneg(), isint()
Feedback	Adaptive hints and messages	wrongans(), showwork(), ifansunit()

Using Macros

Macros are called in the question's setup code or inline within the answer evaluation block. They look like function calls:

$formatted = numfmt($ans, 2);       // format $ans to 2 decimal places
$simplified = fracsimp($num, $den); // simplify a fraction

You can chain macro calls and use their return values in variable assignments, conditional checks, or directly in the question text.

Macros vs. PHP Functions

Many macros parallel standard PHP or math library functions, but are adapted for educational math contexts — for example, fracsimp() returns a properly reduced fraction, and displaynum() handles special cases like negative numbers, zero, and irrational values.

For standard string and array operations, PHP built-ins like strlen(), count(), sort(), and implode() also work directly in question code.

Quick Reference

See each category page for the full list of available macros with examples.