PHP Manual: max

Description

mixed max ( number arg1, number arg2 [, number ...] )

mixed max ( array numbers )

max() returns the numerically highest of the parameter values.

If the first and only parameter is an array, max() returns the highest value in that array. If the first parameter is an integer, string or float, you need at least two parameters and max() returns the biggest of these values. You can compare an unlimited number of values.

Note: PHP will evaluate a non-numeric string as 0, but still return the string if it's seen as the numerically highest value. If multiple arguments evaluate to 0, max() will return a numeric 0 if given, else the alphabetical highest string value will be returned.

Example 1. Example uses of max()

<?php
echo max(1, 3, 5, 6, 7);  // 7
echo max(array(2, 4, 5)); // 5

echo max(0, 'hello');     // 0
echo max('hello', 0);     // hello
echo max(-1, 'hello');    // hello

// With multiple arrays, max compares from left to right
// so in our example: 2 == 2, but 4 < 5
$val = max(array(2, 4, 8), array(2, 5, 7)); // array(2, 5, 7)

// If both an array and non-array are given, the array
// is always returned as it's seen as the largest
$val = max('string', array(2, 5, 7), 42);   // array(2, 5, 7)
?>