PHP Math Functions Tutorial

In this tutorial I will present PHP math functions. They may be needed by a developer in small or complex web applications that are dealing with numbers. I will show you abs(), base_convert(), floor(), fmod(), is_infinite() and others.

abs(nr) – returns the absolute value (with +) of the numbers passed as a parameter to the function.

<?php echo abs(-2.8); echo abs(3); echo abs(-1); ?>

After calling this code the results would be: 2.8 (double / float), 3 (integer) and 1 (integer).

base_convert(nr, base1, base2) – converts a nr. from base1 into base2.

<?php $nr = 18; echo base_convert($nr, 10, 2); ?>

The result would be 10010 (base 2) which represents the value 18 in base 10.

ceil(nr) – returns the rounded value of nr to the next bigger integer.

<?php echo ceil(3.8); echo ceil(4); echo ceil(-2.3); echo ceil(1.2); ?>

The results will be : 4, 4, -3, and 2 .

floor(nr) – is the opposite of ceil.

<?php echo floor(3.8); echo floor(4); echo floor(-2.5); echo floor(1.2); ?>

The results will be: 3, 4, -3, 1.

fmod(x, y) – returns the remainder of x divided to y.

<?php $x = 4.5; $y = 3; $r = fmod($x, $y); ?>

$r will have the value 1.5, because $x divided to $y is 1, remainder is 1.5 .

is_infinite(nr) – returns TRUE if nr is infinite number, FALSE otherwise.

<?php $nr = log(0); if (is_infinite($nr)) echo 'Infinite nr'; ?>

lcg_value() – returns a random number between 0 and 1.

<?php echo lcg_value(); ?>

max(nr1, n2, nr3, ….nr_n) – returns the highest number between nr2 and nr_n. min() does the opposite of max.

<?php echo max(1, 3, 8, 100, 34); ?>

The result will be 100.

mt_rand(min, max) returns a random number between min and max. Same like rand() but mt_rand is four times faster.

<?php echo mt_rand(10, 35); ?> </strong></p> <p><strong>pow(nr, power)</strong> – returns the value of nr at the power of “power”.</p> <p><textarea rows="3" cols="60" readonly="readonly"><?php echo pow(2, 3); ?>

The result is 8.

sqrt(nr) – extracts the square root from nr.

<?php echo sqrt(225); ?>

The result will be 15.

is_numeric(val) – returns TRUE if val is numeric value, FALSE otherwise.

<?php $x = 32/3; if (is_numeric($x)) echo "We have a number with the value: $x"; ?>

Also we have cos, sin, tan, which are taking as a parameter the nr. of degrees (30, 60, 90 etc.) and returns the value in radians.