Removing undefined array indexes after calling array_unique

Question

$almostallTech=array();
$almostallTech[]="no";
$almostallTech[]="no";
$almostallTech[]="yes";
$almostallTech[]="yes";
$almostallTech[]="no";
$almostallTech[]="yes";

$almostallTech=array_unique($almostallTech);
printf("size of array: %d<br/>", sizeof($almostallTech));

for ($x = 0; $x < (sizeof($almostallTech)); $x++) {
    printf("%s", $almostallTech[$x]);
}

After calling the unique method, it returns the size is 2 - which is correct. However the for loop is giving an undefined offset error.

Upon further checking, if I print out:

printf("%s", $almostallTech[0]); - I get no
printf("%s", $almostallTech[2]); - I get yes
printf("%s", $almostallTech[1]); - undefined offset error

So the unique function is removing duplicates but keeping the same index of the former array - which is how it works. This should be simple but can't figure out how to remove the empty or more specifically undefined indexes. Tried the array_filter but still not working. Any suggestions?

What I want is after calling the array_unique method, the duplicates are removed but new indexes should apply. i.e.: I want $almostallTech[0] to contain "no" I want $almostallTech[1] to contain "yes"

What is your expected array result ? It looks normal as you used array_unique(). Read the manual: php.net/function.array-unique — Raptor
– Raptor, Commented Dec 27, 2013 at 8:37
array_values() would be useful to you. check this link php.net/array_values — Sohil Desai
– Sohil Desai, Commented Dec 27, 2013 at 8:51

Amal · Accepted Answer · 2013-12-27 08:39:21Z

8

Because array_unique() does not re-index the array. You'll have to re-index the array numerically, using array_values() or other similar functions:

$almostallTech = array_values($almostallTech);

answered Dec 27, 2013 at 8:39

Amal

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Comments

Nouphal.M · Accepted Answer · 2013-12-27 08:59:44Z

1

Try

 $almostallTech = array_values(array_flip(array_flip($almostallTech)));

Using array_flip keys from array become values and values from array become keys. Thus you could remove the duplicates but still the indexes would be the same. Now you could use array_values function which returns all the values of the array.

edited Dec 27, 2013 at 8:59

answered Dec 27, 2013 at 8:43

Nouphal.M

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6 Comments

Amal Over a year ago

Why is that necessary? Hate to ask, but what do you think array_flip does?

Nouphal.M Over a year ago

In array same keys doesn't exist together,i think you know that.

Amal Over a year ago

So what? Now $almostallTech will be an array of keys, not values -- that's not required. See demo.

Nouphal.M Over a year ago

Oh Sorry man forgot one array_flip. i was also trying to set the demo.

Amal Over a year ago

array_flip(array_flip($arr)) is the same as array_values($arr) --Why is array_flip() necessary? You're flipping the array multiple times only to come back to the original state? The array_flip calls are superfluous.

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