PHP 类型转换 float->int

Question

鉴于此 PHP 代码:

// total is 71.24 (float)
$value = $total * 100;
var_dump($value);
$valuecast = (int)$value;
var_dump($valuecast);
settype($value, 'int');
var_dump($value);

var_dump($value) 给出 float(7124)

var_dump($valuecast) 给出 int(7123)

var_dump($value) after settype 给出 int(7123)

如何获得正确的类型转换？

Answer 1

来自 TypeCasting Float to Integer 上的 PHP 手册

Warning

Never cast an unknown fraction to integer, as this can sometimes lead to unexpected results.

<?php
    echo (int) ( (0.1+0.7) * 10 ); // echoes 7!
?>

See also the warning about float precision.