小數點的運算[討論區- PHP新手區] : 台灣PHP聯盟

http://twpug.net/modules/newbb/viewtopic.php?post_id=10083

Just popping in 註冊日期: 2007/6/10 17:43 文章: 5	<?php $a="1181745772.201471"; $b="1181745772.522440"; $c=$b-$a; echo $c; ?> 以上的程式理論說 $b-$a 的答案應該是 0.320969 但是我跑出來卻是 0.320968866348 請教各位我是否要做什麼變數的型態轉換或是使用什麼運算函數之類的方法才能計算出正確的結果發表日期：2007/6/20 15:06

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sam0228	回覆: 小數點的運算	#2
網站管理員註冊日期: 2005/9/8 17:37 文章: 663	可以用number_format限定顯示的小數 http://tw2.php.net/manual/en/function.number-format.php 發表日期：2007/6/20 15:33
網站管理員註冊日期: 2005/9/8 17:37 文章: 663
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dowdot	回覆: 小數點的運算	#3
Just popping in 註冊日期: 2007/6/10 17:43 文章: 5	感謝您的建議不過我後來找了很久找到了另一個解決的方式運用 BC 高精確度函式庫就是在編譯php時加入以下的參數 --enable-bcmath 之後,就可以使用bcsub、bcadd、bcdiv等函數來運算也可以指定小數點之後的位數感覺蠻方便的這樣,就可以將程式改寫成 $a="1181745772.201471"; $b="1181745772.522440"; echo $c=bcsub($b,$a,6); 發表日期：2007/6/20 22:52

http://tw2.php.net/manual/en/function.number-format.php

Example #1 number_format() Example

For instance, French notation usually use two decimals, comma (',') as decimal separator, and space (' ') as thousand separator. This is achieved with this line :


<?php

$number = 1234.56;

// english notation (default)
$english_format_number = number_format($number);
// 1,235

// French notation
$nombre_format_francais = number_format($number, 2, ',', ' ');
// 1 234,56

$number = 1234.5678;

// english notation without thousands seperator
$english_format_number = number_format($number, 2, '.', '');
// 1234.57

?>

Report a bug


Some programmers may have scripts that use the number_format function
twice on a variable.  However, if a number is 4 or more digits, using
the function twice with only the decimals parameter will lose part of
the value that follows the thousands separator.

<?php

$var = number_format(2234,2);
$var = number_format($var,2);

echo $var;
# Expected Output: 2,234.00

# Actual Output: 2.00
?>


To fix, remove the thousands separator by setting the decimal point and thousands separator parameters like so:

<?php

$var = number_format(2234,2,'.','');
$var = number_format($var,2,'.','');

echo $var;
# Expected Output: 2234.00

# Actual Output: 2234.00
?>


If it's 3 digits or less, then it works normally with only the decimals parameter since there is no thousands separator.

<?php

$var = number_format(123,2);
$var = number_format($var,2);

echo $var;
# Expected Output: 123.00

# Actual Output: 123.00
?>

dipu dot ashok dot 17 at gmail dot com
28-Mar-2010 09:18


function to convert numbers to words

indian: thousand,lakh,crore

Note: function can only convert nos upto 99 crores

<?php 

 $words = array('0'=> '' ,'1'=> 'one' ,'2'=> 'two' ,'3' => 'three','4' => 'four','5' => 'five','6' => 'six','7' => 'seven','8' => 'eight','9' => 'nine','10' => 'ten','11' => 'eleven','12' => 'twelve','13' => 'thirteen','14' => 'fouteen','15' => 'fifteen','16' => 'sixteen','17' => 'seventeen','18' => 'eighteen','19' => 'nineteen','20' => 'twenty','30' => 'thirty','40' => 'fourty','50' => 'fifty','60' => 'sixty','70' => 'seventy','80' => 'eighty','90' => 'ninty','100' => 'hundred &','1000' => 'thousand','100000' => 'lakh','10000000' => 'crore');

function no_to_words($no)

{    global $words;

    if($no == 0)

        return ' ';

    else {           $novalue='';$highno=$no;$remainno=0;$value=100;$value1=1000;        

            while($no>=100)    {

                if(($value <= $no) &&($no  < $value1))    {

                $novalue=$words["$value"];

                $highno = (int)($no/$value);

                $remainno = $no % $value;

                break;

                }

                $value= $value1;

                $value1 = $value * 100;

            }        

          if(array_key_exists("$highno",$words))

              return $words["$highno"]." ".$novalue." ".no_to_words($remainno);

          else { 

             $unit=$highno%10;

             $ten =(int)($highno/10)*10;             

             return $words["$ten"]." ".$words["$unit"]." ".$novalue." ".no_to_words($remainno);

           }

    }

}

echo no_to_words(999978987);

?>

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小數點的運算[討論區- PHP新手區] : 台灣PHP聯盟

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