PHP: get number of decimal digits

Question

Is there a straightforward way of determining the number of decimal places in a(n) integer/double value in PHP? (that is, without using explode)

Answer 1

I needed a solution that works with various number formats and came up with the following algorithms:

// Count the number of decimal places
$current = $value - floor($value);
for ($decimals = 0; ceil($current); $decimals++) {
    $current = ($value * pow(10, $decimals + 1)) - floor($value * pow(10, $decimals + 1));
}

// Count the total number of digits (includes decimal places)
$current = floor($value);
for ($digits = $decimals; $current; $digits++) {
    $current = floor($current / 10);
}

Results:

input:    1
decimals: 0
digits:   1

input:    100
decimals: 0
digits:   3

input:    0.04
decimals: 2
digits:   2

input:    10.004
decimals: 3
digits:   5

input:    10.0000001
decimals: 7
digits:   9

input:    1.2000000992884E-10
decimals: 24
digits:   24

input:    1.2000000992884e6
decimals: 7
digits:   14

Answer 2

Here's a function that takes into account trailing zeroes:

function get_precision($value) {
    if (!is_numeric($value)) { return false; }
    $decimal = $value - floor($value); //get the decimal portion of the number
    if ($decimal == 0) { return 0; } //if it's a whole number
    $precision = strlen($decimal) - 2; //-2 to account for "0."
    return $precision; 
}

Answer 3

$str = "1.23444";
print strlen(substr(strrchr($str, "."), 1));

Answer 4

Something like:

<?php

$floatNum = "120.340304";
$length = strlen($floatNum);

$pos = strpos($floatNum, "."); // zero-based counting.

$num_of_dec_places = ($length - $pos) - 1; // -1 to compensate for the zero-based count in strpos()

?>

This is procedural, kludgy and I wouldn't advise using it in production code. But it should get you started.

Answer 5

$decnumber = strlen(strstr($yourstr,'.'))-1

Answer 6

I used the following to determine whether a returned value has any decimals (actual decimal values, not just formatted to display decimals like 100.00):

if($mynum - floor($mynum)>0) {has decimals;} else {no decimals;}