PHP Remove Duplicate Values

PHP Remove Duplicate Values: In this tutorial you will come to know about how to remove the duplicate values, PHP provides array_unique() function, in this tutorial you will come to know about its general format, parameters, return value. The example will exemplify the function of this function

PHP Array Remove Duplicate Values

In PHP if we need to remove duplicate values then we can use array_unique() function. The functionality of it is to accept an array and returns another array without duplicate values.

General description of array_unique() is given below:

General Format	array array_unique(array $array [, int $sort_flags=sort_string] )
Parameters	array: Input array	sort_flags: The second optional parameter is used to compare items as follows SORT_REGULAR - Normal SORT_NUMERIC - Numerically SORT_STRING - As string SORT_LOCALE_STRING - As string, based on the current locale.
Return Value	Another array without duplicate values

Example 1:

<?php

$array=array('cricket'=>11,'football'=>11,'chess'=>2);

echo" Initially the values of \$array is: ";

var_dump($array);

echo" After removing the duplicates: ";

print_r(array_unique($array));

Output:

Initially the values of $array is:
array(3) {
  ["cricket"]=>
  int(11)
  ["football"]=>
  int(11)
  ["chess"]=>
  int(2)
}

After removing the duplicates:
Array
(
    [cricket] => 11
    [chess] => 2
)

Example 2:

<?php

$array=array("a"=>"adenine","axerophthol","angstrom","b"=>"bacillus","angstrom","barn");

echo" Initially the values of \$array is: ";

var_dump($array);

echo" After removing the duplicates: ";

print_r(array_unique($array));

Output:

Initially the values of $array is:
array(6) {
  ["a"]=>
  string(7) "adenine"
  [0]=>
  string(11) "axerophthol"
  [1]=>
  string(8) "angstrom"
  ["b"]=>
  string(8) "bacillus"
  [2]=>
  string(8) "angstrom"
  [3]=>
  string(4) "barn"
}

After removing the duplicates:
Array
(
    [a] => adenine
    [0] => axerophthol
    [1] => angstrom
    [b] => bacillus
    [3] => barn
)

Example 3:

<?php

$array=array("1",1,"1","2","2","2",2,2,2,2,3,3,3);

echo" Initially the values of \$array is: ";

var_dump($array);

echo" After removing the duplicates: ";

print_r(array_unique($array));

Output:

Initially the values of $array is:
array(13) {
  [0]=>
  string(1) "1"
  [1]=>
  int(1)
  [2]=>
  string(1) "1"
  [3]=>
  string(1) "2"
  [4]=>
  string(1) "2"
  [5]=>
  string(1) "2"
  [6]=>
  int(2)
  [7]=>
  int(2)
  [8]=>
  int(2)
  [9]=>
  int(2)
  [10]=>
  int(3)
  [11]=>
  int(3)
  [12]=>
  int(3)
}

After removing the duplicates:
Array
(
    [0] => 1
    [3] => 2
    [10] => 3
)

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