It's not explicitly documented; number_format also rounds:
<?php
$numbers = array(0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009);
foreach ($numbers as $number)
print $number."->".number_format($number, 2, '.', ',')."<br>";
?>
0.001->0.00
0.002->0.00
0.003->0.00
0.004->0.00
0.005->0.01
0.006->0.01
0.007->0.01
0.008->0.01
0.009->0.01
number_format
(PHP 4, PHP 5, PHP 7, PHP 8)
number_format — 以千位分隔符方式格式化一个数字
说明
number_format(
float
int
?string
?string
): string
float
$num,int
$decimals = 0,?string
$decimal_separator = ".",?string
$thousands_separator = ","): string
使用四舍五入的规则，将数字格式化为千位分组和小数位（可选）。
参数
-
num -
要格式化的数字。
-
decimals -
设置小数位数。如果为
0，则从返回值中忽略decimal_separator。 -
decimal_separator -
指定小数点的分隔符。
-
thousands_separator -
设置千位分隔符。
返回值
num 的格式化版本。
更新日志
| 版本 | 说明 |
|---|---|
| 8.0.0 | 在此版本之前，number_format() 接受一个、两个或四个参数（不会是三个）。 |
| 7.2.0 |
number_format() 现在再也不会返回 -0，之前
num 为 -0.01 的情况下可以返回 -0。
|
示例
示例 #1 number_format() 示例
例如，法语计数通常使用两位小数，逗号（“,”）作为小数分隔符，空格（“ ”）作为千位分隔符。以下示例展示了格式化数字的各种方法：
<?php
$number = 1234.56;
// 英文计数（默认）
$english_format_number = number_format($number);
// 1,235
// 法语计数
$nombre_format_francais = number_format($number, 2, ',', ' ');
// 1 234,56
$number = 1234.5678;
// 没有千位分隔符的英文计数
$english_format_number = number_format($number, 2, '.', '');
// 1234.57
?>
add a note
User Contributed Notes 10 notes
thomas at weblizards dot de ¶
15 years ago
Jeroen de Bruijn [NL] ¶
19 years ago
If you want to display a number ending with ,- (like 200,-) when there are no decimal characters and display the decimals when there are decimal characters i use:
function DisplayDouble($value)
{
list($whole, $decimals) = split ('[.,]', $value, 2);
if (intval($decimals) > 0)
return number_format($value,2,".",",");
else
return number_format($value,0,".",",") .",-";
}
info at ensostudio dot ru ¶
2 years ago
Note: use NumberFormatter to convert in human-readable format instead user function from comments:
<?php
echo NumberFormatter::create('en', NumberFormatter::SPELLOUT)->format(12309); // twelve thousand three hundred nine
echo NumberFormatter::create('ru', NumberFormatter::SPELLOUT)->format(12307.5); // двенадцать тысяч триста семь целых пять десятых
?>
james at bandit dot co.nz ¶
15 years ago
Outputs a human readable number.
<?php
# Output easy-to-read numbers
# by james at bandit.co.nz
function bd_nice_number($n) {
// first strip any formatting;
$n = (0+str_replace(",","",$n));
// is this a number?
if(!is_numeric($n)) return false;
// now filter it;
if($n>1000000000000) return round(($n/1000000000000),1).' trillion';
else if($n>1000000000) return round(($n/1000000000),1).' billion';
else if($n>1000000) return round(($n/1000000),1).' million';
else if($n>1000) return round(($n/1000),1).' thousand';
return number_format($n);
}
?>
Outputs:
247,704,360 -> 247.7 million
866,965,260,000 -> 867 billion
MarcM ¶
18 years ago
For Zero fill - just use the sprintf() function
$pr_id = 1;
$pr_id = sprintf("%03d", $pr_id);
echo $pr_id;
//outputs 001
-----------------
$pr_id = 10;
$pr_id = sprintf("%03d", $pr_id);
echo $pr_id;
//outputs 010
-----------------
You can change %03d to %04d, etc.
Theo Diem ¶
21 years ago
formatting numbers may be more easy if u use number_format function.
I also wrote this :
function something($number)
{
$locale = localeconv();
return number_format($number,
$locale['frac_digits'],
$locale['decimal_point'],
$locale['thousands_sep']);
}
hope this helps =)
[]'s
stm555 at hotmail dot com ¶
19 years ago
I ran across an issue where I wanted to keep the entered precision of a real value, without arbitrarily rounding off what the user had submitted.
I figured it out with a quick explode on the number before formatting. I could then format either side of the decimal.
<?php
function number_format_unlimited_precision($number,$decimal = '.')
{
$broken_number = explode($decimal,$number);
return number_format($broken_number[0]).$decimal.$broken_number[1];
}
?>
Mad Max ¶
1 year ago
India (~18% of the world's population), Pakistan (~3%), Bangladesh (~2%), Nepal, and Myanmar, have a different way to display large numbers:
10,23,45,678.20
The first thousand is "normal" but then there is a comma every TWO digits after that.
Now look at the number_format() function. Do you see a way to control the placement and frequency of the commas? Or a mode option/switch to deal with displaying numbers for almost 1/4 of the total population on Earth? Neither do I.
If you are developing an application for an international audience, the ICU-based Intl PHP extension might work fine for you. However, IBM's ICU library is a resource heavy library (because...IBM), isn't the fastest library on the planet (also normal for IBM), ICU formatters are somewhat unreliable/inconsistent (yup, still IBM), and the Intl extension isn't always available in PHP (this one's PHP). So there are many significant hurdles to overcome just to prepare a number for display using the Intl extension.
In short, approximately 23% of the planet currently can't use this function for displaying large numbers and there isn't a good built-in *lightweight* alternative other than to roll your own solution that outright replaces this function. Formatting a number for display is an extremely common task.
Disclaimer: This comment serves as a warning to others that this function isn't suitable for an international audience in its current state. This comment is not a question, bug report, or feature request. I'm simply commenting on the current state of affairs with this function. If someone opts to make changes/improvements, then great, but that's not the purpose here.
liviu andrei (bls) ¶
13 years ago
To prevent the rounding that occurs when next digit after last significant decimal is 5 (mentioned by several people below):
<?php
function fnumber_format($number, $decimals='', $sep1='', $sep2='') {
if (($number * pow(10 , $decimals + 1) % 10 ) == 5) //if next not significant digit is 5
$number -= pow(10 , -($decimals+1));
return number_format($number, $decimals, $sep1, $sep2);
}
$t=7.15;
echo $t . " | " . number_format($t, 1, '.', ',') . " | " . fnumber_format($t, 1, '.', ',') . "\n\n";
//result is: 7.15 | 7.2 | 7.1
$t=7.3215;
echo $t . " | " . number_format($t, 3, '.', ',') . " | " . fnumber_format($t, 3, '.', ',') . "\n\n";
//result is: 7.3215 | 7.322 | 7.321
} ?>
have fun!
support at piri dot sk ¶
1 year ago
My simpler solution to the problem of the decimal number in this function being longer than the specified number of decimals.
Standard result for number_format() is..
number_format(5.00098, 2) = 5.00
My function will return the result = 5.001
<?php
// ** Warning: Does not work with scientific notation. Conversion to a real number is required. **
echo auto_decimal_format(5.0005620); // print 5.0006
echo auto_decimal_format(5.0009820); // print 5.001
echo auto_decimal_format(5.00098, 8); // print 5.00098000
echo auto_decimal_format(1.0295691366783E-5, 2); // print 0.00
function auto_decimal_format($n, $def = 2) {
$a = explode(".", $n);
if (count($a)>1) {
$b = str_split($a[1]);
$pos = 1;
foreach ($b as $value) {
if ($value != 0 && $pos >= $def) {
$c = number_format($n, $pos);
$c_len = strlen(substr(strrchr($c, "."), 1));
if ($c_len > $def) { return rtrim($c, 0); }
return $c; // or break
}
$pos++;
}
}
return number_format($n, $def);
}
?>
