How to counting varians data from array?

Question

I have an array like this

$arr = array(1,2,1,3,2,4);

How to count total of variant data from that array ?

example :

$arr = array(1,2,1,3,2,4);

total = 4

Are you trying to count the number of unique values in an array? Have you considered looking at the PHP documentation? Specifically, array_unique and count. — kainaw
– kainaw, Commented Jun 6, 2016 at 14:45

Steve · Accepted Answer · 2016-06-06 14:54:17Z

1

You can flip the array, and check its length:

echo count(array_flip($arr));

This works because an array index must be unique, so you end up with one element for every unique item in the original array:

http://php.net/manual/en/function.array-flip.php

If a value has several occurrences, the latest key will be used as its value, and all others will be lost.

This is (was?) somewhat faster than array_unique, but unless you are calling this a LOT, array_unique is a lot more descriptive, so probably the better option

edited Jun 6, 2016 at 14:54

answered Jun 6, 2016 at 14:44

Steve

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kainaw · Accepted Answer · 2016-06-06 14:46:58Z

1

If you are trying to count the unique values in an array, this is very straightforward and rather obvious:

echo count(array_unique($arr));

answered Jun 6, 2016 at 14:46

kainaw

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4 Comments

Steve Over a year ago

Ha, good point, no idea why my brain landed on using a side effect from array_flip when array_unique is clearly designed for the task

kainaw Over a year ago

I didn't want to use array_flip because it will change the value in rare cases. Example: "04" and "4" will both become integer 4.

Steve Over a year ago

Fair enough, i wasnt suggesting flip was better, quite the opposite, though a quick google has suggested my brain wasnt completely broken: stackoverflow.com/questions/8321620/array-unique-vs-array-flip i must have come to this conclusion in the past but forgot why

kainaw Over a year ago

Correct. array_flip is faster. Also, the error is rare. If the values are all integers, then array_flip is better. I just don't know the scope of the true problem and my main point is that the person should make some attempt to read the documentation before asking a question. count and array_unique should be very easy to find.

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