ceil

(PHP 4, PHP 5, PHP 7, PHP 8)

ceil — 进一法取整

说明

ceil(int|float $num): float

如果有必要，通过对 num 向上取整返回下一个最高的整数。

参数

num: 要进一法取整的值

返回值

返回不小于 num 的下一个整数。ceil() 返回的类型仍然是 float，因为 float 值的范围通常比 int 要大。

更新日志

版本	说明
8.0.0	`num` 不再接受支持数字转换的内部对象。

示例

示例 #1 ceil() 示例

<?php
echo ceil(4.3);    // 5
echo ceil(9.999);  // 10
echo ceil(-3.14);  // -3
?>

参见

floor() - 舍去法取整
round() - 对浮点数进行四舍五入

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＋添加备注

用户贡献的备注 5 notes

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Scott Weaver / scottmweaver * gmail ¶

16 years ago

I needed this and couldn't find it so I thought someone else wouldn't have to look through a bunch of Google results-

<?php

// duplicates m$ excel's ceiling function
if( !function_exists('ceiling') )
{
    function ceiling($number, $significance = 1)
    {
        return ( is_numeric($number) && is_numeric($significance) ) ? (ceil($number/$significance)*$significance) : false;
    }
}

echo ceiling(0, 1000);     // 0
echo ceiling(1, 1);        // 1000
echo ceiling(1001, 1000);  // 2000
echo ceiling(1.27, 0.05);  // 1.30

?>

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eep2004 at ukr dot net ¶

6 years ago

Caution!
<?php
$value = 77.4;
echo ceil($value * 100) / 100;         // 77.41 - WRONG!
echo ceil(round($value * 100)) / 100;  // 77.4 - OK!

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steve_phpnet // nanovox \\ com ¶

19 years ago

I couldn't find any functions to do what ceiling does while still leaving I specified number of decimal places, so I wrote a couple functions myself.  round_up is like ceil but allows you to specify a number of decimal places.  round_out does the same, but rounds away from zero.

<?php
 // round_up:
 // rounds up a float to a specified number of decimal places
 // (basically acts like ceil() but allows for decimal places)
 function round_up ($value, $places=0) {
  if ($places < 0) { $places = 0; }
  $mult = pow(10, $places);
  return ceil($value * $mult) / $mult;
 }

 // round_out:
 // rounds a float away from zero to a specified number of decimal places
 function round_out ($value, $places=0) {
  if ($places < 0) { $places = 0; }
  $mult = pow(10, $places);
  return ($value >= 0 ? ceil($value * $mult):floor($value * $mult)) / $mult;
 }

 echo round_up (56.77001, 2); // displays 56.78
 echo round_up (-0.453001, 4); // displays -0.453
 echo round_out (56.77001, 2); // displays 56.78
 echo round_out (-0.453001, 4); // displays -0.4531
?>

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oktam ¶

13 years ago

Actual behaviour:
echo ceil(-0.1); //result "-0" but i expect "0"

Workaround:
echo ceil(-0.1)+0; //result "0"

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frozenfire at php dot net ¶

12 years ago

Please see http://www.php.net/manual/en/language.types.float.php for information regarding floating point precision issues.