我有一个像这样的数组
$data = array(
"163",
"630",
"43",
"924",
"4",
"54"
);
我该如何根据字符串长度而非数值大小从中选择最小和最大值,(在此示例中为1(最小)和3(最大))。
我有一个像这样的数组
$data = array(
"163",
"630",
"43",
"924",
"4",
"54"
);
我该如何根据字符串长度而非数值大小从中选择最小和最大值,(在此示例中为1(最小)和3(最大))。
看起来你应该使用一个array_map()
// Convert array to an array of string lengths
$lengths = array_map('strlen', $data);
// Show min and max string length
echo "The shortest is " . min($lengths) .
". The longest is " . max($lengths);
请注意,$lengths
数组是未排序的,因此您可以轻松地检索每个字符串长度的相应数字。
array_map('strlen', $data)
来实现同样的效果。 - NullUserExceptionstrlen
- 它是以字节为单位的字符串长度,而不是字符数。在特殊(多字节)字符的情况下,字符数更大,因此必须使用 mb_strlen
。 - mikep这是 brian_d的代码 的改进版本:
$min = PHP_INT_MAX;
$max = -1;
foreach ($data as $a) {
$length = strlen($a);
$max = max($max, $length);
$min = min($min, $length);
}
$min
和 $max
),除非你正在处理一个巨大的数组,而你只想遍历一次。 - Peter Ajtai虽然在这种情况下不建议这样做,因为你将遍历数组两次,但你也可以使用array_reduce来将每个元素与其余元素进行比较。就像这样:
<?php
$data = array('163','630','43','42','999','31');
//Will return the longest element that is nearest to the end of the array (999)
//That's why we use strlen() on the result.
$max_l = strlen(array_reduce($data,'maxlen'));
//Will return the shortest element that is nearest to the end of the array (31)
$min_l = strlen(array_reduce($data,'minlen'));
echo "The longest word is $max_l characters, while the shortest is $min_l\n";
function maxlen($k,$v) {
if (strlen($k) > strlen($v)) return $k;
return $v;
}
function minlen($k,$v) {
if ($k == '') return PHP_INT_MAX;
if (strlen($k) < strlen($v)) return $k;
return $v;
}
?>
<?php
$max_l = strlen(array_reduce($data,
function ($k,$v) { return (strlen($k) > strlen($v)) ? $k : $v; }
));
$min_l = strlen(array_reduce($data,
function ($k,$v) {
if (!$k) return PHP_INT_MAX;
return (strlen($k) < strlen($v)) ? $k : $v;
}
));
echo "The longest word is $max_l characters, while the shortest is $min_l\n";
?>
$min = 100;
$max = -1;
foreach($data as $a){
$length = strlen($a);
if($length > $max){ $max = $length; }
else if($length < $min){ $min = $length; }
}
$min
必须从一个非常大的数字开始(例如 int32.maxvalue?) - Femareffor
循环更容易实现)。 - Matthew$min=100, $max = -1
。因此,假设您现在有一个非空数组,则没有其他条件与for ($i = 1; $i < $len; ++$i)
。实际上,您避免了第一次迭代时的if/else(因为它被跳过)。此外,foreach
往往是PHP中最差的迭代方式。但这些都是小问题,我离题了... - Matthew<?php
$array = array(
"163",
"630",
"43",
"924",
"4",
"54"
);
$arraycopy = array_map('strlen',$array);
asort($arraycopy);
$min = reset($arraycopy);
//if you need a single 'minword'
$minword = $array[key($arraycopy)];
//if you need them all
$minwords = array_intersect_key($array,array_flip(array_keys($arraycopy,$min)));
$max = end($arraycopy);
//if you need a single 'maxword'
$maxword = $array[key($arraycopy)];
//if you need them all:
$maxwords = array_intersect_key($array,array_flip(array_keys($arraycopy,$max)));
var_dump($min,$max,$minword,$maxword,$minwords,$maxwords);
为了完整起见,这里有一个一行代码实现最大值和最小值:
$maximum = max(array_map('strlen', $array));
$minimum = min(array_map('strlen', $array));