PHP - Check if all the elements of an array are in a string

Question

I have an array, $my_array, containing n element and a string, $my_string. I want to check if ALL the elements of $my_array are in $my_string. The order in which they are found in the string is not important as long as they are all there. I'm looking for the most efficient solution to get a TRUE only if all of the elements are present.

TRUE:

$my_array = array("big", "blue", "sky", "dog"); 
$my_string = "my big dog loves the blue sky";

FALSE:

$my_array = array("big", "blue", "sky", "dog"); 
$my_string = "the big blue sky";

I could do it in a loop, I just wanted to know if there is a built in function in php to do so — LaGuille
– LaGuille, Commented Dec 31, 2014 at 20:52
@LaGuille: You can try array_diff or array_intersect, if you do something like explode(' ', $my_string). — gen_Eric
– gen_Eric, Commented Dec 31, 2014 at 20:54
Do you want exact words, with punctuation included? As i pointed out it makes a difference ( pun intended ). — ArtisticPhoenix
– ArtisticPhoenix, Commented Dec 31, 2014 at 21:30

ArtisticPhoenix · Accepted Answer · 2014-12-31 21:35:43Z

3

Here you go, don't be afraid of arrays.

  $my_array = array("big", "blue", "sky", "dog");
  $my_string = "my big dog loves the blue sky"

  function arrayInString( array $my_array, $my_string ){
    $my_string = explode(' ', $my_string);
    // difference return all elements of array one not in array two
    $diff = array_diff($my_array, $my_string);
    if(empty( $diff )){
        //if there is no difference there are no elements not in the string.
        return true;
    }
    return false;
 }

Fun without loops!

If there is punctuation you can use

preg_split('/^\w/', $my_string );

instead of explode

edited Dec 31, 2014 at 21:35

answered Dec 31, 2014 at 21:14

ArtisticPhoenix

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1 Comment

ArtisticPhoenix Over a year ago

@Hobbes - Thanks. Others have similar suggestions as well.

Rizier123 · Accepted Answer · 2014-12-31 20:57:23Z

1

This should work for you:

<?php

    $my_array = array("big", "blue", "sky", "dog"); 
    $my_string = "my big dog loves the blue sky"; 

    $result = 0;

    foreach($my_array as $value) {
        if (strpos($my_string, $value) !== false) 
            $result+=1; 
    }

    if($result == count($my_array))
        echo "true";
    else
        echo "false";

?>

Output:

true

answered Dec 31, 2014 at 20:57

Rizier123

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1 Comment

ArtisticPhoenix Over a year ago

strpos will find partial matches so is "my big dog loves the blue sky" the same as "mybigdoglovesthebluesky" or are we looking for words. Is "dog" the same as "dogs"

SpYk3HH · Accepted Answer · 2014-12-31 21:07:47Z

1

2 ways I can think of. This first way is great, if you know for sure you'll always be able to split be a given character(s). It's short, sweet, and simple. Making use of array_dif and a simple explode

function isArrayInString($str, $ara, $splitter=" ") {
    $ret = array_diff($ara, explode($splitter, $str));
    return empty($ret);
}

However, that doesn't seem very dynamic and limits you based on "splitting" the string. An easier, possibly better way, would be to loop through your array and ensure every value of the array exist in the string by using strpos.

function isArrayInString($str, $ara, $splitter=" ") {
    foreach($ara as $v) if (strpos($str , $v) === false) return FALSE;
    return $TRUE;
}

So something like:

$myArray = array("big", "blue", "sky", "dog"); 
$myString = "my big dog loves the blue sky"; 
echo isArrayInString($myString, $myArray);

Will output TRUE

While something like:

$myArray = array("big", "blue", "sky", "dog"); 
$myString = "the big blue sky";
echo isArrayInString($myString, $myArray);

Will output FALSE

edited Dec 31, 2014 at 21:07

answered Dec 31, 2014 at 20:59

SpYk3HH

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2 Comments

ArtisticPhoenix Over a year ago

The big advantage from the second example is when punctuation is used. Just thought I would point that out, however strpos may find partial string matches. Such as dog in dogs, which may or may not be the intended result.

ArtisticPhoenix Over a year ago

I realize that that was why i deleted that comment a while ago.

Waldson Patricio · Accepted Answer · 2014-12-31 21:03:34Z

0

function allInString($str, $arr) {
    foreach ($arr as $a) {
       if (strpos($str, $a) === false) {
           return false;
       }
    }
    return true;
}

answered Dec 31, 2014 at 21:03

Waldson Patricio

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1 Comment

MZaragoza Over a year ago

it would help if you also explain what you are doing more than just copy and paste some code

terary · Accepted Answer · 2014-12-31 21:10:23Z

-1

$my_array = array("big", "blue", "sky", "dog");
$my_string = "my big dog loves the blue sky";
$inArray = true;

foreach($my_array as $field)
{
    if(!strpos($my_string,$field))
    {echo "$field is not";
        return false;}
}
return true;

answered Dec 31, 2014 at 21:10

terary

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4 Comments

Mike Over a year ago

You can delete the $inArray = true; line. It does nothing.

terary Over a year ago

Yeah you are probably right - I am an old man and back in day - it was wise to be complete - old habits. Good call though.

ArtisticPhoenix Over a year ago

@terary I would leave it, even in today's 'day' you can get undefined variable errors, never hurts to set a default.

Mike Over a year ago

@ArtisiticPhoenix but it's not even used anywhere else in the code but here. It does absolutely nothing.

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