显示一个数字到小数点后两位

Question

What's the correct way to round a PHP string to two decimal places?

$number = "520"; // It's a string from a database

$formatted_number = round_to_2dp($number);

echo $formatted_number;

The output should be 520.00 ;

How should the round_to_2dp() function definition be?

Answer 1

You can use number_format() :

return number_format((float)$number, 2, '.', '');

Example:

$foo = "105";
echo number_format((float)$foo, 2, '.', '');  // Outputs -> 105.00

This function returns a string .

Answer 2

Use round() (use if you are expecting a number in float format only, else use number_format() as an answer given by Codemwnci ):

echo round(520.34345, 2);   // 520.34
echo round(520.3, 2);       // 520.3
echo round(520, 2);         // 520

From the manual:

Description:

 float round(float $val [, int $precision = 0 [, int $mode = PHP_ROUND_HALF_UP ]]);

Returns the rounded value of val to specified precision (number of digits after the decimal point). precision can also be negative or zero (default).

...

Example #1 round() examples

<?php echo round(3.4); // 3 echo round(3.5); // 4 echo round(3.6); // 4 echo round(3.6, 0); // 4 echo round(1.95583, 2); // 1.96 echo round(1241757, -3); // 1242000 echo round(5.045, 2); // 5.05 echo round(5.055, 2); // 5.06 ?>

Example #2 mode examples

<?php echo round(9.5, 0, PHP_ROUND_HALF_UP); // 10 echo round(9.5, 0, PHP_ROUND_HALF_DOWN); // 9 echo round(9.5, 0, PHP_ROUND_HALF_EVEN); // 10 echo round(9.5, 0, PHP_ROUND_HALF_ODD); // 9 echo round(8.5, 0, PHP_ROUND_HALF_UP); // 9 echo round(8.5, 0, PHP_ROUND_HALF_DOWN); // 8 echo round(8.5, 0, PHP_ROUND_HALF_EVEN); // 8 echo round(8.5, 0, PHP_ROUND_HALF_ODD); // 9 ?>

Answer 3

或者，

$padded = sprintf('%0.2f', $unpadded); // 520 -> 520.00

Answer 4

http://php.net/manual/en/function.round.php

eg

echo round(5.045, 2);    // 5.05

echo round(5.055, 2);    // 5.06

Answer 5

Try:

$number = 1234545454; 
echo  $english_format_number = number_format($number, 2); 

The output will be:

1,234,545,454.00

Answer 6

You can use the PHP printf or sprintf functions:

Example with sprintf :

$num = 2.12;
echo sprintf("%.3f", $num);

You can run the same without echo as well. Example: sprintf("%.3f", $num);

Output:

2.120

Alternatively, with printf :

echo printf("%.2f", $num);

Output:

2.124

Answer 7

Use the PHP number_format() function.

For example,

$num = 7234545423;
echo number_format($num, 2);

The output will be:

7,234,545,423.00

Answer 8

解决此问题的另一种更奇特的方法是将bcadd()与 $right_operand 为0的虚拟值一起使用。

$formatted_number = bcadd($number, 0, 2);

Answer 9

$retailPrice = 5.989;
echo number_format(floor($retailPrice*100)/100,2, '.', ''); 

It will return 5.98 without rounding the number.

Answer 10

bcdiv($number, 1, 2) // 2 varies for digits after the decimal point

This will display exactly two digits after the decimal point.

Advantage:

If you want to display two digits after a float value only and not for int, then use this.

Answer 11

Here I get two decimals after the . (dot) using a function...

function truncate_number($number, $precision = 2) {

    // Zero causes issues, and no need to truncate
    if (0 == (int)$number) {
        return $number;
    }

    // Are we negative?
    $negative = $number / abs($number);

    // Cast the number to a positive to solve rounding
    $number = abs($number);

    // Calculate precision number for dividing / multiplying
    $precision = pow(10, $precision);

    // Run the math, re-applying the negative value to ensure
    // returns correctly negative / positive
    return floor( $number * $precision ) / $precision * $negative;
}

Results from the above function:

echo truncate_number(2.56789, 1); // 2.5
echo truncate_number(2.56789);    // 2.56
echo truncate_number(2.56789, 3); // 2.567

echo truncate_number(-2.56789, 1); // -2.5
echo truncate_number(-2.56789);    // -2.56
echo truncate_number(-2.56789, 3); // -2.567

New Correct Answer

Use the PHP native function bcdiv

echo bcdiv(2.56789, 1, 1);  // 2.5
echo bcdiv(2.56789, 1, 2);  // 2.56
echo bcdiv(2.56789, 1, 3);  // 2.567
echo bcdiv(-2.56789, 1, 1); // -2.5
echo bcdiv(-2.56789, 1, 2); // -2.56
echo bcdiv(-2.56789, 1, 3); // -2.567

Answer 12

使用 PHP number_format()函数。

Answer 13

For conditional rounding off ie. show decimal where it's really needed otherwise whole number

123.56 => 12.56

123.00 => 123

$somenumber = 123.56;

$somenumber = round($somenumber,2);

if($somenumber == intval($somenumber))
{
    $somenumber = intval($somenumber);
}

echo $somenumber; // 123.56


$somenumber = 123.00;

$somenumber = round($somenumber,2);

if($somenumber == intval($somenumber))
{
    $somenumber = intval($somenumber);
}

echo $somenumber; // 123    

Answer 14

I make my own.

$decimals = 2;
$number = 221.12345;
$number = $number * pow(10, $decimals);
$number = intval($number);
$number = $number / pow(10, $decimals);

Answer 15

round_to_2dp is a user-defined function, and nothing can be done unless you posted the declaration of that function.

However, my guess is doing this: number_format($number, 2);

Answer 16

$twoDecNum = sprintf('%0.2f', round($number, 2));

舍入正确地舍入数字，如果舍入后恰好只有 1 个小数位，sprintf 会强制它保留 2 个小数位。

Answer 17

If you want to use two decimal digits in your entire project, you can define:

bcscale(2);

Then the following function will produce your desired result:

$myvalue = 10.165445;
echo bcadd(0, $myvalue);
// result=10.11

But if you don't use the bcscale function, you need to write the code as follows to get your desired result.

$myvalue = 10.165445;
echo bcadd(0, $myvalue, 2);
// result=10.11

To know more

• BC Math Functions

• bcscale

Answer 18

$number = sprintf('%0.2f', $numbers); // 520.89898989 -> 520.89

这将为您提供 2 个小数点后的数字。

Answer 19

use roud(yourValue,decimalPoint) or number_format(yourValue,decimalPoint);

number_format() return value as string like this type 1,234.67 . so in this case you can not use it for addition or any calculation. if you try then you have to deal with Number Format Error ...

In this case round(121222.299000000,2) will be better option. The result would be 121222.29 ...

Answer 20

Number without round

$double = '21.188624';
echo intval($double) . '.' . substr(end(explode('.', $double)), 0, 2);

Answer 21

Adding to other answers, since number_format() will, by default, add thousands separator.

To remove this, do this:

$number = number_format($number, 2, ".", "");

Answer 22

Here's another solution with strtok and str_pad :

$num = 520.00
strtok(round($num, 2), '.') . '.' . str_pad(strtok('.'), 2, '0')

Answer 23

• Choose the number of decimals
• Format commas(,)
• An option to trim trailing zeros

Once and for all!

function format_number($number,$dec=0,$trim=false){
  if($trim){
    $parts = explode(".",(round($number,$dec) * 1));
    $dec = isset($parts[1]) ? strlen($parts[1]) : 0;
  }
  $formatted = number_format($number,$dec); 
  return $formatted;
}

Examples

echo format_number(1234.5,2,true); //returns 1,234.5
echo format_number(1234.5,2);      //returns 1,234.50
echo format_number(1234.5);        //returns 1,235

Answer 24

如果你像我一样使用math equation你可以这样设置：

{math equation="x + y" x=4.4444 y=5.0000 format="%.2f"}

Answer 25

这就是我今天遇到的同一个问题，想要对一个数字进行四舍五入并将浮点值返回到给定的小数位，并且它不能是字符串（从 number_format 返回）答案是

echo sprintf('%.' . $decimalPlaces . 'f', round($number, $decimalPlaces));

Answer 26

You can use PHP round() function.

echo round(3.4);         // 3
echo round(3.5);         // 4
echo round(3.6);         // 4
echo round(3.6, 0);      // 4
echo round(1.95583, 2);  // 1.96
echo round(1241757, -3); // 1242000
echo round(5.045, 2);    // 5.05
echo round(5.055, 2);    // 5.06