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phparraysunique

Append dot and counter as suffix for values encountered more than once like R's make.unique function

I need the same functionality of R function make.unique in PHP.

In R:

> dup_array = c("a", "b", "a", "c")
> make.unique(dup_array)
[1] "a"   "b"   "a.1" "c"

In PHP:

> dup_array = array("a", "b", "a", "c")
> magic_function(dup_array)

What is the magic_function?

Solution

  • Well, there are no in-built functions already for this as yet, however, you can create your own custom function for it.

    Keep track of current frequency of the element using a dictionary(associative array) and then attach the current frequency accordingly.

    <?php

function makeUnique($arr){
    $set = [];
    foreach($arr as $k => $v){
        $set[ $v ] = ($set[ $v ] ?? 0) + 1;
        $arr[ $k ] = $arr[ $k ] . ($set[ $v ] > 1 ? '.' .($set[ $v ] - 1) : '');
    }
    return $arr;
}

print_r(makeUnique($arr));

    Online Demo