Functions

Functions name reusable work and return values to the caller.

functions.php

<?php
function square($value) {
    return $value * $value;
}

$side = ;
$area = square($side);

echo "side=" . $side . "\n";
echo "area=" . $area . "\n";

<?php
function square($value) {
    return $value * $value;
}

$side = ;
$area = square($side);

echo "side=" . $side . "\n";
echo "area=" . $area . "\n";

<?php
function square($value) {
    return $value * $value;
}

$side = ;
$area = square($side);

echo "side=" . $side . "\n";
echo "area=" . $area . "\n";

function call A function call runs the named function and can use the returned value in another expression.