如何使用PHP向下舍入到下一个x20号码？

Question

I know ceil, which will round 15.1 to 16 and 31.2 to 32. But how to round up to the next x20 number? like 15.1 to 20 and 31,2 to 40?

Is needed to make sensefull labels for the y-axis of a chart.

Answer 1

Try this (works in JavaScript):

$result = 20 * ceil($input / 20);

Here, we're rounding to 20 . To round to other numbers, simply replace 20 with whatever base you want. The documentation for ceil() can be found here .

A function that does the same:

function roundTo($value, $base)
{
    return $base * ceil($value / $base);
}

---

As a small aside, if you want to round to the nearest base, instead of rounding up , use round() instead of ceil() .

Answer 2

除以20并使用ceil，然后乘以20

Answer 3

或者您可以使用模数：

echo round($a + 20 - ($a % 20));

Answer 4

If you want "mid-range" values to round more, you can use the following .

function roundTo($n,$i = 1){
  $r = $n % $i;
  $d = round(($n - $r * $i) / $i);
  return $r * $i + $d * $i;
}

for ($a = 0; $a < 100; $a++){
  printf("%d = %d\r\n", $a, ceil2($a, 20));
}

The above produces:

Number:    Rounded To:
0-10       0
11-30      20
31-50      40
etc.

This more closely simulates how 1.3=1 but 1.5=2 .

Answer 5

you can use this

ceil(x/2)*2