PHP: How do I check the contents of an array for my string?

Question

I a string that is coming from my database table say $needle. If te needle is not in my array, then I want to add it to my array.

If it IS in my array then so long as it is in only twice, then I still want to add it to my array (so three times will be the maximum)

In order to check to see is if $needle is in my $haystack array, do I need to loop through the array with strpos() or is there a quicker method ?

There are many needles in the table so I start by looping through the select result.

This is the schematic of what I am trying to do...

$haystack = array();

  while( $row = mysql_fetch_assoc($result)) {
   $needle = $row['data'];

    $num = no. of times $needle is in $haystack //   $haystack is an array

    if ($num < 3 ) {
        $$haystack[] = $needle; // hopfully this adds the needle
        }

     } // end while. Get next needle.

Does anyone know how do I do this bit:

$num = no. of times $needle is in $haystack

thanks

miek · Accepted Answer · 2010-01-25 07:13:24Z

1

You can use array_count_values() to first generate a map containing the frequency for each value, and then only increment the value if the value count in the map was < 3, for instance:

$original_values_count = array_count_values($values);

foreach ($values as $value)
    if ($original_values_count[$value] < 3)
        $values[] = $value;

As looping cannot be completely avoided, I'd say it's a good idea to opt for using a native PHP function in terms of speed, compared to looping all values manually.

edited Jan 25, 2010 at 7:13

answered Jan 25, 2010 at 7:08

miek

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Kara · Accepted Answer · 2013-11-19 20:55:09Z

1

Did you mean array_count_values() to return the occurrences of all the unique values?

<?php
$a=array("Cat","Dog","Horse","Dog");
print_r(array_count_values($a));
?>

The output of the code above will be:

Array ( 
[Cat] => 1,
[Dog] => 2,
[Horse] => 1
 )

edited Nov 19, 2013 at 20:55

Kara

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answered Jan 25, 2010 at 7:05

Haim Evgi

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Sejanus · Accepted Answer · 2010-01-25 07:12:00Z

0

There is also array_map() function, which applies given function to every element of array.

answered Jan 25, 2010 at 7:12

Sejanus

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user259175 · Accepted Answer · 2010-01-26 12:39:51Z

0

Maybe something like the following? Just changing Miek's code a little.

$haystack_count = array_count_values($haystack);
if ($haystack_count[$needle] < 3)
    $haystack[] = $needle;

answered Jan 26, 2010 at 12:39

user259175

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