1. array() 

It Returns an array of the parameters. The parameters can be given an index with the => operator

Parameters

• key(Optional): It specifies the key, of type numeric or string. If not set, an integer key is generated, starting at 0
• value(Required) : It specifies the value

Return Values: It returns an array of the parameters.

Syntax

array(key1 => value1, key2 => value2...)

Example

<?php
    $array_val= array("val1"=>"computer", "val2"=>"laptop", "val3"=>"mouse");
    print_r($array_val);
?>

Output : Array ( [val1] => computer [val2] => laptop [val3] => mouse )

2. array_change_key_case()

It returns an array with all keys from input lowercased or uppercased. Numbered indices are left as is.

Parameters

• input: The array to work on
• case: Either CASE_UPPER or CASE_LOWER (default)

Return Values: It returns an array with its keys lower or uppercased, or false if the input is not an array.

Syntax

array array_change_key_case ( array $input [, int $case] )

Example

<?php
   $inputVal = array("FirSt"=> 100, "SecOnd" => 40);
   print_r(array_change_key_case($inputVal, CASE_UPPER));
?> 

Output : Array ( [FIRST] => 100 [SECOND] => 40 )

3. array_count_values()

• It returns an array using the values of the input array as keys and their frequency in input as values.

Parameters

• input: The array of values to count

Return Values: It returns an associative array of values from the input as keys and their count as value.

Syntax

array array_count_values ( array $input );

Example

<?php
   $input = array("orange", "mango", "banana", "orange" );
   print_r(array_count_values($input));
?> 

Output : Array ( [orange] => 2 [mango] => 1 [banana => 1 )

4. array_combine()

 It creates an array by using the values from the keys array as keys and the values from the values array as the corresponding values.

Parameters

• keys: Array of keys to be used
• values: Array of values to be used

Return Values: It returns the combined array, FALSE if the number of elements for each array isn't equal or if the arrays are empty.

Syntax

array array_combine ( array $keys, array $values );

Example

<?php 
   $abc = array("green","red","yellow");
   $bcd = array("mango","apple", "banana");
   $cde = array_combine($abc, $bcd);
   print_r($cde);
?> 

Output : Array([green] => mango [red] => apple [yellow] => banana)

5. array_chunk()

It chunks an array into a size large chunks. The last chunk may contain less than size elements.

Parameters

• input: The array to work on
• size: The size of each chunk
• preserve_keys: When set to TRUE keys will be preserved. Default is FALSE which will reindex the chunk numerically

Return Values: It returns a multidimensional numerically indexed array

Syntax

array array_chunk ( array $input, int $size [, bool $preserve_keys] );

Example

<?php
   $input = array("apple","mango", "orange","banana","grapes");
   print_r(array_chunk($input, 4));
   print_r(array_chunk($input, 2, true));
?> 

Output : Array ( [0] => Array ( [0] => apple[1] => mango[2] => orange[3] => banana) [1] => Array ( [0] => grapes) ) Array ( [0] => Array ( [0] => apple[1] => mango) [1] => Array ( [2] => orange[3] => banana) [2] => Array ( [4] => grapes) )