PHP 数组中最短/最长的字符串
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PHP shortest/longest string in array
提问by Mark Lalor
I have an arraylike this
我有一个这样的数组
$data = array(
"163",
"630",
"43",
"924",
"4",
"54"
);
How can I select the smallest and largest valuesfrom it according to string lengthNOT number value. (for this example it is 1 (smallest) and 3 (largest).
我怎样才能选择最小值和最大值从它根据字符串长度不数值。 （对于这个例子，它是 1（最小）和 3（最大）。
回答by Peter Ajtai
Seems like you should use an array_map()
似乎您应该使用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);
Note that the $lengthsarray is unsorted, so you can easily retrieve the corresponding number for each string length.
请注意，该$lengths数组是未排序的，因此您可以轻松检索每个字符串长度的相应数字。
回答by NullUserException
Here's an improved version of brian_d's code:
这是brian_d 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);
}
回答by Vinko Vrsalovic
Although in this case it is not advisable because you'll be traversing the array twice, you can also use array_reduceto compare each element against the rest. Like this:
尽管在这种情况下不建议这样做，因为您将遍历数组两次，但您也可以使用array_reduce将每个元素与其余元素进行比较。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;
}
?>
If you are using PHP 5.3.0+ you can take advantage of closures:
如果您使用的是 PHP 5.3.0+，您可以利用闭包：
<?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";
?>
回答by brian_d
$min = 100;
$max = -1;
foreach($data as $a){
$length = strlen($a);
if($length > $max){ $max = $length; }
else if($length < $min){ $min = $length; }
}
回答by Wrikken
<?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);
回答by Typewar
For completion, here is a one-liner for maximum and minimum:
为了完成，这里是最大和最小的单行：
$maximum = max(array_map('strlen', $array));
$minimum = min(array_map('strlen', $array));
