How to search array of string in another string in PHP? - php

Question

Firstly, I want to inform that, what I need is the reverse of in_array PHP function.
I need to search all items of array in the string if any of them found, function will return true otherwise return false.
I need the fastest solution to this problem, off course this can be succeeded by iterating the array and using the strpos function.
Any suggestions are welcome.
Example Data:
$string = 'Alice goes to school every day';
$searchWords = array('basket','school','tree');
returns true
$string = 'Alice goes to school every day';
$searchWords = array('basket','cat','tree');
returns false

Answer 1

You should try with a preg_match:
if (preg_match('/' . implode('|', $searchWords) . '/', $string)) return true;
After some comments here a properly escaped solution:
function contains($string, Array $search, $caseInsensitive = false) {
$exp = '/'
. implode('|', array_map('preg_quote', $search))
. ($caseInsensitive ? '/i' : '/');
return preg_match($exp, $string) ? true : false;
}

Answer 2

function searchWords($string,$words)
{
foreach($words as $word)
{
if(stristr($string," " . $word . " ")) //spaces either side to force a word
{
return true;
}
}
return false;
}
Usage:
$string = 'Alice goes to school every day';
$searchWords = array('basket','cat','tree');
if(searchWords($string,$searchWords))
{
//matches
}
Also take note that the function stristr is used to make it not case-sensitive

Answer 3

As per the example of malko, but with properly escaping the values.
function contains( $string, array $search ) {
return 0 !== preg_match(
'/' . implode( '|', preg_quote( $search, '/' ) ) . '/',
$string
);
}

Answer 4

If string can be exploded using space following will work:
var_dump(array_intersect(explode(' ', $str), $searchWords) != null);
OUTPUT: for 2 examples you've provided:
bool(true)
bool(false)
Update:
If string cannot be exploded using space character, then use code like this to split string on any end of word character:
var_dump(array_intersect(preg_split('~\b~', $str), $searchWords) != null);

Answer 5

There is always debate over what is faster so I thought I'd run some tests using different methods.
Tests Run:
strpos
preg_match with foreach loop
preg_match with regex or
indexed search with string to explode
indexed search as array (string already exploded)
Two sets of tests where run. One on a large text document (114,350 words) and one on a small text document (120 words). Within each set, all tests were run 100 times and then an average was taken. Tests did not ignore case, which doing so would have made them all faster. Test for which the index was searched were pre-indexed. I wrote the code for indexing myself, and I'm sure it was less efficient, but indexing for the large file took 17.92 seconds and for the small file it took 0.001 seconds.
Terms searched for included: gazerbeam (NOT found in the document), legally (found in the document), and target (NOT found in the document).
Results in seconds to complete a single test, sorted by speed:
Large File:
0.0000455808639526 (index without explode)
0.0009979915618897 (preg_match using regex or)
0.0011657214164734 (strpos)
0.0023632574081421 (preg_match using foreach loop)
0.0051533532142639 (index with explode)
Small File
0.000003724098205566 (strpos)
0.000005958080291748 (preg_match using regex or)
0.000012607574462891 (preg_match using foreach loop)
0.000021204948425293 (index without explode)
0.000060625076293945 (index with explode)
Notice that strpos is faster than preg_match (using regex or) for small files, but slower for large files. Other factors, such as the number of search terms will of course affect this.
Algorithms Used:
//strpos
$str = file_get_contents('text.txt');
$t = microtime(true);
foreach ($search as $word) if (strpos($str, $word)) break;
$strpos += microtime(true) - $t;
//preg_match
$str = file_get_contents('text.txt');
$t = microtime(true);
foreach ($search as $word) if (preg_match('/' . preg_quote($word) . '/', $str)) break;
$pregmatch += microtime(true) - $t;
//preg_match (regex or)
$str = file_get_contents('text.txt');
$orstr = preg_quote(implode('|', $search));
$t = microtime(true);
if preg_match('/' . $orstr . '/', $str) {};
$pregmatchor += microtime(true) - $t;
//index with explode
$str = file_get_contents('textindex.txt');
$t = microtime(true);
$ar = explode(" ", $str);
foreach ($search as $word) {
$start = 0;
$end = count($ar);
do {
$diff = $end - $start;
$pos = floor($diff / 2) + $start;
$temp = $ar[$pos];
if ($word < $temp) {
$end = $pos;
} elseif ($word > $temp) {
$start = $pos + 1;
} elseif ($temp == $word) {
$found = 'true';
break;
}
} while ($diff > 0);
}
$indexwith += microtime(true) - $t;
//index without explode (already in array)
$str = file_get_contents('textindex.txt');
$found = 'false';
$ar = explode(" ", $str);
$t = microtime(true);
foreach ($search as $word) {
$start = 0;
$end = count($ar);
do {
$diff = $end - $start;
$pos = floor($diff / 2) + $start;
$temp = $ar[$pos];
if ($word < $temp) {
$end = $pos;
} elseif ($word > $temp) {
$start = $pos + 1;
} elseif ($temp == $word) {
$found = 'true';
break;
}
} while ($diff > 0);
}
$indexwithout += microtime(true) - $t;

Answer 6

try this:
$string = 'Alice goes to school every day';
$words = split(" ", $string);
$searchWords = array('basket','school','tree');
for($x = 0,$l = count($words); $x < $l;) {
if(in_array($words[$x++], $searchWords)) {
//....
}
}

Answer 7

Below prints the frequency of number of elements found from the array in the string
function inString($str, $arr, $matches=false)
{
$str = explode(" ", $str);
$c = 0;
for($i = 0; $i<count($str); $i++)
{
if(in_array($str[$i], $arr) )
{$c++;if($matches == false)break;}
}
return $c;
}

Answer 8

Below link will help you : just need to customize as you required.
Check if array element exists in string
customized:
function result_arrayInString($prdterms,208){
if(arrayInString($prdterms,208)){
return true;
}else{
return false;
}
}
This may be helpful to you.