Variable handling 函数
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floatval

(PHP 4 >= 4.2.0, PHP 5)

floatval — 获取变量的浮点值

描述

float floatval ( mixed $var )

返回变量 var 的 float 数值。

var 可以是任何标量类型。你不能将 floatval() 用于数组或对象。

<?php
$var = '122.34343The';
$float_value_of_var = floatval ($var);
print $float_value_of_var; // 打印出 122.34343
?>

参见 intval()、strval()、settype() 和 类型戏法。

Variable handling 函数
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PHP手册
PHP手册 - N: 获取变量的浮点值

用户评论:

PapaPinguoin (31-Oct-2011 03:26)

To view the very large and very small numbers (eg from a database DECIMAL), without displaying scientific notation, or leading zeros.

FR : Pour afficher les très grand et très petits nombres (ex. depuis une base de données DECIMAL), sans afficher la notation scientifique, ni les zéros non significatifs.

<?php
function floattostr( $val )
{
    preg_match( "#^([\+\-]|)([0-9]*)(\.([0-9]*?)|)(0*)$#", trim($val), $o );
    return $o[1].sprintf('%d',$o[2]).($o[3]!='.'?$o[3]:'');
}
?>

<?php
echo floattostr("0000000000000001");
echo floattostr("1.00000000000000");
echo floattostr("0.00000000001000");
echo floattostr("0000.00010000000");
echo floattostr("000000010000000000.00000000000010000000000");
echo floattostr("-0000000000000.1");
echo floattostr("-00000001.100000");

// result
// 1
// 1
// 0.00000000001
// 0.0001
// 10000000000.0000000000001
// -0.1
// -1.1

?>

secretr at NOSPAM dot e107 dot org (03-Jan-2011 04:37)

setlocale() and floatval() duo could break your DB queries in a very simple way:

<?php
setlocale(LC_ALL, 'bg_BG', 'bgr_BGR');
echo floatval(0.15); // output 0,15
?>

You would need simple workaround like:

<?php
function number2db($value)
{
    $larr = localeconv();
    $search = array(
        $larr['decimal_point'],
        $larr['mon_decimal_point'],
        $larr['thousands_sep'],
        $larr['mon_thousands_sep'],
        $larr['currency_symbol'],
        $larr['int_curr_symbol']
    );
    $replace = array('.', '.', '', '', '', '');

    return str_replace($search, $replace, $value);
}

setlocale(LC_ALL, 'bg_BG', 'bgr_BGR');
$testVal = floatval(0.15); // result 0,15
var_dump($testVal, number2db($testVal));

// Result:
// float(0,15)
// string(4) "0.15"
?>

balai01 at yahoo dot com (13-Oct-2010 11:56)

//changes comma to dot if any
//removes any currency symbol and gets the floatVar

$price_fl_point=(preg_replace("/,/",".",$price));
$price_c=floatval(preg_replace("/^[^0-9\.]/","",$price_fl_point));

chris at georgakopoulos dot com (29-Jul-2009 04:12)

locale aware floatval:

<?php
function ParseFloat($floatString){
    $LocaleInfo = localeconv();
    $floatString = str_replace($LocaleInfo["mon_thousands_sep"] , "", $floatString);
    $floatString = str_replace($LocaleInfo["mon_decimal_point"] , ".", $floatString);
    return floatval($floatString);
}
?>

ted devito (10-Mar-2009 05:10)

i noticed all (well, unless i missed something) the functions working with decimals destroy trailing decimal places. this function restores them in case you want to be able to display a consistent precision for users.

<?php
function decimal($val, $precision = 0) {
    if ((float) $val) :
        $val = round((float) $val, (int) $precision);
        list($a, $b) = explode('.', $val);
        if (strlen($b) < $precision) $b = str_pad($b, $precision, '0', STR_PAD_RIGHT);
        return $precision ? "$a.$b" : $a;
    else : // do whatever you want with values that do not have a float
        return $val;
    endif;
}
?>

info at marc-gutt dot de (26-Aug-2008 11:55)

<?php
function floatvalue($value) {
     return floatval(preg_replace('#^([-]*[0-9\.,\' ]+?)((\.|,){1}([0-9-]{1,2}))*$#e', "str_replace(array('.', ',', \"'\", ' '), '', '\\1') . '.\\4'", $value));
}
?>

It is much shorter and able to handle those one, too:
xx,-
xx,--
xx'xxx,xx

After using floatvalue() you can go forward with number_format() as usual.

Michiel (30-Jul-2008 01:21)

The last getFloat() function is not completely correct.

1.000.000 and 1,000,000 and its negative variants are not correctly parsed. For the sake of comparing and to make myself clear I use the name parseFloat in stead of getFloat for the new function:

<?php
function parseFloat($ptString) {
            if (strlen($ptString) == 0) {
                    return false;
            }
           
            $pString = str_replace(" ", "", $ptString);
           
            if (substr_count($pString, ",") > 1)
                $pString = str_replace(",", "", $pString);
           
            if (substr_count($pString, ".") > 1)
                $pString = str_replace(".", "", $pString);
           
            $pregResult = array();
       
            $commaset = strpos($pString,',');
            if ($commaset === false) {$commaset = -1;}
       
            $pointset = strpos($pString,'.');
            if ($pointset === false) {$pointset = -1;}
       
            $pregResultA = array();
            $pregResultB = array();
       
            if ($pointset < $commaset) {
                preg_match('#(([-]?[0-9]+(\.[0-9])?)+(,[0-9]+)?)#', $pString, $pregResultA);
            }
            preg_match('#(([-]?[0-9]+(,[0-9])?)+(\.[0-9]+)?)#', $pString, $pregResultB);
            if ((isset($pregResultA[0]) && (!isset($pregResultB[0])
                    || strstr($preResultA[0],$pregResultB[0]) == 0
                    || !$pointset))) {
                $numberString = $pregResultA[0];
                $numberString = str_replace('.','',$numberString);
                $numberString = str_replace(',','.',$numberString);
            }
            elseif (isset($pregResultB[0]) && (!isset($pregResultA[0])
                    || strstr($pregResultB[0],$preResultA[0]) == 0
                    || !$commaset)) {
                $numberString = $pregResultB[0];
                $numberString = str_replace(',','',$numberString);
            }
            else {
                return false;
            }
            $result = (float)$numberString;
            return $result;
}
?>

Comparing of float parsing functions with the following function:

<?php
function testFloatParsing() {
    $floatvals = array(
        "22 000,76",
        "22.000,76",
        "22,000.76",
        "22 000",
        "22,000",
        "22.000",
        "22000.76",
        "22000,76",
        "1.022.000,76",
        "1,022,000.76",
        "1,000,000",
        "1.000.000",
        "1022000.76",
        "1022000,76",
        "1022000",
        "0.76",
        "0,76",
        "0.00",
        "0,00",
        "1.00",
        "1,00",
        "-22 000,76",
        "-22.000,76",
        "-22,000.76",
        "-22 000",
        "-22,000",
        "-22.000",
        "-22000.76",
        "-22000,76",
        "-1.022.000,76",
        "-1,022,000.76",
        "-1,000,000",
        "-1.000.000",
        "-1022000.76",
        "-1022000,76",
        "-1022000",
        "-0.76",
        "-0,76",
        "-0.00",
        "-0,00",
        "-1.00",
        "-1,00"
    );
   
    echo "<table>
        <tr>
            <th>String</th>
            <th>floatval()</th>
            <th>getFloat()</th>
            <th>parseFloat()</th>
        </tr>";
       
    foreach ($floatvals as $fval) {
        echo "<tr>";
        echo "<td>" . (string) $fval . "</td>";
       
        echo "<td>" . (float) floatval($fval) . "</td>";
        echo "<td>" . (float) getFloat($fval) . "</td>";
        echo "<td>" . (float) parseFloat($fval) . "</td>";
        echo "</tr>";
    }
    echo "</table>";
}
?>

steve at opilo dot net (21-Jul-2008 02:07)

Most of the functions listed here that deal with $ and , are unnecessarily complicated. You can use ereg_replace() to strip out ALL of the characters that will cause floatval to fail in one simple line of code:

<?php $output = floatval(ereg_replace("[^-0-9\.]","",$input)); ?>

leprau at leprau dot de (19-Jul-2007 05:26)

For those of you, who are looking for a function that rips the first,
but longest possible float (or at least integer) from a string,
like 123.45 from the string "Price: 123,45$"

If no useable value is found, the function returns false.

Checks for both comma and dot as decimal-separator,
but does not check for 3 digits between thousands,
so 1,234.5 is as valid as 1,23,4.5 (both will return 1234.5)

12,.3 will return 12
1,000,000 will return 1000.0 !

(if thousands separator is defined,
decimals should be defined too ...
in fact I was too lazy to check for that too)

Here you go, and feel free to optimize the function ;)
<?php
function getFloat($pString) {
    if (strlen($pString) == 0) {
            return false;
    }
    $pregResult = array();

    $commaset = strpos($pString,',');
    if ($commaset === false) {$commaset = -1;}

    $pointset = strpos($pString,'.');
    if ($pointset === false) {$pointset = -1;}

    $pregResultA = array();
    $pregResultB = array();

    if ($pointset < $commaset) {
        preg_match('#(([-]?[0-9]+(\.[0-9])?)+(,[0-9]+)?)#', $pString, $pregResultA);
    }
    preg_match('#(([-]?[0-9]+(,[0-9])?)+(\.[0-9]+)?)#', $pString, $pregResultB);
    if ((isset($pregResultA[0]) && (!isset($pregResultB[0])
            || strstr($preResultA[0],$pregResultB[0]) == 0
            || !$pointset))) {
        $numberString = $pregResultA[0];
        $numberString = str_replace('.','',$numberString);
        $numberString = str_replace(',','.',$numberString);
    }
    elseif (isset($pregResultB[0]) && (!isset($pregResultA[0])
            || strstr($pregResultB[0],$preResultA[0]) == 0
            || !$commaset)) {
        $numberString = $pregResultB[0];
        $numberString = str_replace(',','',$numberString);
    }
    else {
        return false;
    }
    $result = (float)$numberString;
    return $result;
}
?>

aa at geb-team dot de (04-Sep-2006 04:03)

@pillepop2003 at yahoo dot de

<?php
float('-100.00', array('single_dot_as_decimal' => true)); // whoops, returns -10000
?>

use: "/^[0-9-]*[\.]{1}[0-9-]+$/"
instead of: "/^[0-9]*[\.]{1}[0-9-]+$/"

(19-Apr-2005 01:30)

you can also use typecasting instead of functions:

(float) $value;

pillepop2003 at yahoo dot de (14-Dec-2004 10:38)

Use this snippet to extract any float out of a string. You can choose how a single dot is treated with the (bool) 'single_dot_as_decimal' directive.
This function should be able to cover almost all floats that appear in an european environment.

<?php

    function float($str, $set=FALSE)
    {           
        if(preg_match("/([0-9\.,-]+)/", $str, $match))
        {
            // Found number in $str, so set $str that number
            $str = $match[0];
           
            if(strstr($str, ','))
            {
                // A comma exists, that makes it easy, cos we assume it separates the decimal part.
                $str = str_replace('.', '', $str);    // Erase thousand seps
                $str = str_replace(',', '.', $str);    // Convert , to . for floatval command
               
                return floatval($str);
            }
            else
            {
                // No comma exists, so we have to decide, how a single dot shall be treated
                if(preg_match("/^[0-9]*[\.]{1}[0-9-]+$/", $str) == TRUE && $set['single_dot_as_decimal'] == TRUE)
                {
                    // Treat single dot as decimal separator
                    return floatval($str);
                   
                }
                else
                {
                    // Else, treat all dots as thousand seps
                    $str = str_replace('.', '', $str);    // Erase thousand seps
                    return floatval($str);
                }               
            }
        }
       
        else
        {
            // No number found, return zero
            return 0;
        }
    }

// Examples

echo float('foo 123,00 bar'); // returns 123.00
echo float('foo 123.00 bar' array('single_dot_as_decimal'=> TRUE)); //returns 123.000
echo float('foo 123.00 bar' array('single_dot_as_decimal'=> FALSE)); //returns 123000
echo float('foo 222.123.00 bar' array('single_dot_as_decimal'=> TRUE)); //returns 222123000
echo float('foo 222.123.00 bar' array('single_dot_as_decimal'=> FALSE)); //returns 222123000

// The decimal part can also consist of '-'
echo float('foo 123,-- bar'); // returns 123.00

?>

Big Up.
Philipp

anonymous at start dot be (16-Jun-2004 03:00)

Easier-to-grasp-function for the ',' problem.

<?php
function Getfloat($str) {
  if(strstr($str, ",")) {
    $str = str_replace(".", "", $str); // replace dots (thousand seps) with blancs
    $str = str_replace(",", ".", $str); // replace ',' with '.'
  }
 
  if(preg_match("#([0-9\.]+)#", $str, $match)) { // search for number that may contain '.'
    return floatval($match[0]);
  } else {
    return floatval($str); // take some last chances with floatval
  }
}

echo Getfloat("$ 19.332,35-"); // will print: 19332.35
?>

vickers at hotpop dot com (26-Jan-2004 11:45)

floatval() does not work with "$35,234.43", as it could not handle the '$' and the ','.  The following takes care of all values, such that only numeric and the decimal sign are input into floatval().  (It probably shows I'm an old 'c' guy)...this function only lightly tested.

<?php
function strtflt($str) {
    $il = strlen($str);
    $flt = "";
    $cstr = "";
   
    for($i=0;$i<$il;$i++) {
        $cstr = substr($str, $i, 1);
        if(is_numeric($cstr) || $cstr == ".")
            $flt = $flt.$cstr;
    }
    return floatval($flt);
}
?>

Richard Vickers
vickers@hotpop.com

Zipi (25-Apr-2003 10:51)

This function converts a string to a float no matter is the decimal separator dot (.) or comma (,). It also converts integers correctly. It takes the digits from the beginning of the string and ignores all other characters.

<?php
function floatval($strValue) {
   $floatValue = ereg_replace("(^[0-9]*)(\\.|,)([0-9]*)(.*)", "\\1.\\3", $strValue);
   if (!is_numeric($floatValue)) $floatValue = ereg_replace("(^[0-9]*)(.*)", "\\1", $strValue);
   if (!is_numeric($floatValue)) $floatValue = 0;
   return $floatValue;
  }
?>

-Zipi (Finland)

jason at shadonet dot com (08-Mar-2003 03:07)

Instead of using floatval which only appeared in PHP 4.2 you could juse use $variable = (float)$variable

This function doesn't seem to add any functionality that wasn't already there.