Best way to initialize empty array in PHP

Arrays in PHP: Use array() Function to create an array in PHP. There are three types of array supported in PHP:

  • Indexed arrays: Arrays having a numeric index.
  • Associative arrays: Arrays having named keys.
  • Multidimensional arrays: It contains one or more array in particular array.

Note: Why it is always good practice to declare an empty array and then push the items to that array?
When declare an empty array and then start entering elements in it later. With the help of this, it can prevent different errors due to a faulty array. It helps to have the information of using bugged, rather having the array. It saves time during the debugging. Most of the time it may not have anything to add to the array at the point of creation.

Syntax to create an empty array:

$emptyArray = []; 
$emptyArray = array();
$emptyArray = (array) null;

While push an element to the array it can use $emptyArray[] = “first”. At this time, $emptyArray contains “first”, with this command and sending “first” to the array which is declared empty at starting.

In other words, the initialization of new array is faster, use syntax var first = [] rather while using syntax var first = new Array(). The fact is being a constructor function the function Array() and the, [] is a part of the literal grammar of array. Both are complete and executed in completely different ways. Both are optimized and not bothered by the overhead of any of the calling functions.



Basic example of empty array:

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<?php
  
$emptyArray = (array) null;
  
var_dump($emptyArray);
?>

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Output:

array(0) {
}

Now PHP 5.4, which supports [] as an alternative, As per the compiler concerned it was synonymous and most of the PHP developers uses $array = [] as it makes going back and forth between JS and PHP easier.

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<?php
  
/* method to create Empty array. */
$firstempty = [];
echo "Created First empty array <br>";
      
/* method to create Second Empty array. */
$second = array( );
echo "Created second empty array<br>";
      
/* First method to create array. */
$first = array( 1, 2);
          
foreach( $first as $value ) {
    echo "Value is $value <br>";
}
          
/* Second method to create array. */
$first[0] = "one";
$first[1] = "two";
          
foreach( $first as $value ) {
    echo "Value is $value <br>";
}
?>

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Output:

Created First empty array 
Created second empty array
Value is 1
Value is 2
Value is one
Value is two

Another Method:

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<?php
  
// Create an empty array
$emptyArray=array();
  
// Push elements to the array
array_push($emptyArray, "geeks", "for", "geeks");
  
// Display array elements
print_r($emptyArray);
?>

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Output:

Array
(
    [0] => geeks
    [1] => for
    [2] => geeks
)


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