PHP - 在字符串中查找特定字符长度的最常见字词。

Question

Ok, so as I'm getting my hands dirty with PHP I've started playing around with arrays, strings and the like.

Now I know that arrays have a neat feature called "array_count_values" which can help to determine what the most repeated entry is. I wasn't able to find a string equivalent for this- will I need to convert the string to an array?

Basically, I want my code to determine what the most common (repeated) word is over a certain length in a given string.

Sans the character length qualification, this code can find the answer to the question of what is the most repeated word in an array:

<?php


$param[0]="Ted";
$param[1]="Mark";
$param[2]="Mark";
$param[3]="Ross"; 
$param[3]="Clarence"; 

function array_most_common($arr) 
{ 
  $counted = array_count_values($arr); 
  arsort($counted); 
  return(key($counted));     
}

$mostCommon = array_most_common($param);
echo $mostCommon;
?>

So what would make this doable with a string? And a character amount filter?

Answer 1

With a string, you can just explode() or preg_split() on space to form an array. Using preg_split() is favorable as it will eliminate duplicate and extraneous whitespace that explode() will not.

$array = preg_split( '/\s+/', "This is a pretty long long long string", -1, PREG_SPLIT_NO_EMPTY);

Then, once you have an array, use array_filter() to remove those that don't meet the character requirements:

$threshold = 3;
$filtered = array_filter( $array, function( $el) use( $threshold) {
    return strlen( $el) > $threshold;
});

Once you have the $filtered array, just use that in array_count_values().

$counts = array_count_values( $filtered);
arsort( $counts); 
echo key( $counts) . ' -> ' . current( $counts); 

Here is a demo, which prints:

long -> 3