How to remove duplicate words from string using php? [duplicate] - php

Question

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remove duplicate from string in PHP
(2 answers)
Closed 5 years ago.
Below is the variable I have,
$string = 'AAA,BBB,aAA,BbB,AAA,BbB';
I need the unique string result below,
$string = 'AAA,BBB,aAA,BbB';
How to make it unique just like array_unique() function , is there any default String function to remove duplicate string in PHP?

Answer 1

I don't know if php have such function, but you can process it like this: live demo
$raw = 'AAA,BBB,aAA,BbB,AAA,BbB';
$string = implode(',', array_unique(explode(',', $raw)));

Answer 2

For the record, I fully support Kris' method, and that is the way I would choose if this were for my project. However, I would just like to add that there are several additional ways to skin this cat:
Code: (Demo)
$raw = 'AAA,BBB,aAA,BbB,BbB,AAA';
// str_word_count() -> array_unique() -> implode()
echo implode(',',array_unique(str_word_count($raw,1)));
echo "\n";
// str_getcsv() -> array_unique() -> implode()
echo implode(',',array_unique(str_getcsv($raw)));
echo "\n";
// preg_match_all() -> array_unique() -> join()
echo join(',',array_unique(preg_match_all("/[A-Za-z]{3}/",$raw,$m)?$m[0]:array()));
echo "\n";
// preg_split() -> array_unique() -> join()
echo join(',',array_unique(preg_split("/,/",$raw)));
echo "\n";
// preg_replace() -> parse_str() -> implode()
parse_str(preg_replace('/(^|,)([A-Za-z]{3})/',"$2=$2&",$raw),$array);
echo implode(',',$array);
I have 5 different methods to explode the csv string without using explode().
1 method that doesn't use array_unique.
And of course implode() and join() can be used interchangeably as they are synonyms.
I think the fifth method is my favorite as it is the wackiest and doesn't use array_unique(). *unfortunately it's a two-liner :{
p.s.
#Thiyagu says this is how the string is constructed:
forloop(){ $string .= $a[i].',';}
If that is true, then weeding out the duplicates can be done inside this loop by leveraging a temporary array. This has the added benefit of omitting the trailing comma that concatenation generates.
foreach($data as $value){
$result[$value]=$value; // duplicate values will be overwritten because arrays may not have two identical keys
}
echo implode(',',$result);