为什么小数没有正确排序:
13
11
14
10
12.5
---------------------------------------------------------
descending order:
14
12.5
13
11
10
使用此代码:
class Customer {
public $score;
public function __construct($score) {
$this->score = $score;
}
}
$customers = [];
$customers[] = new Customer(13);
$customers[] = new Customer(11);
$customers[] = new Customer(14);
$customers[] = new Customer(10);
$customers[] = new Customer(12.5);
if(is_array($customers) && count($customers) > 0)
{
foreach($customers as $customer)
{
echo '<div>'.$customer->score.'</div>';
}
}
echo '<hr/>';
echo '<div>descending order:</div>';
usort($customers, function($a, $b) {
return $b->score - $a->score;
});
if(is_array($customers) && count($customers) > 0)
{
foreach($customers as $customer)
{
echo '<div>'.$customer->score.'</div>';
}
}
将
十进制0.5
转换为整数会将其更改为0
。将 usort 函数更改为:
usort($customers, function($a, $b) {
if($b->score - $a->score >= 0){
return 1;
}
return -1;
});
输出:
descending order:
14
13
12.5
11
10
PHP手册 说:
警告:从比较函数返回非整数值, 例如浮点数,将导致内部强制转换为整数 回调的返回值。因此,诸如 0.99 和 0.1 之类的值都将是 强制转换为整数值 0,这将比较以下值: 平等。
尝试
usort($customers, function($a, $b) {
return strnatcmp($b->score,$a->score);
});
usort($customers, function($a, $b) {
return (int)$b->score - (int)$a->score;
});
例如,您的输入是14.9,14
和14.5
,输出是14.9,14
和14.5
,它被视为14.9=14,14.0=14
和14.5=14