Best way to initialize empty array in PHP

Arrays in PHP: Use the array() function to create arrays in PHP.

PHP supports three types of arrays:

Indexed array: An array with a numeric index.

Associative array: an array with named keys.

Multidimensional array: It contains one or more arrays within a specific array.

Note: Why is it always good practice to declare an empty array and then push items to that array?

Declare an empty array and start entering elements into it. With the help of this, it prevents different errors due to array failure. It helps to get information using bugs instead of using arrays. It saves time during debugging. Most of the time, there may not be anything to add to the array at creation time.

Syntax for creating an empty array:

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

When pushing elements to an array, you can use $emptyArray[]="first". At this point, $emptyArray contains "first", use this command and send "first" to the array, which is declared empty on startup.

In other words, a new array is initialized faster using the syntax var first =[] instead of using the syntax var first = new array(). In fact, the function Array() is a constructor, and [] is part of the literal syntax of arrays. Both are done and executed in completely different ways. They are optimized and do not suffer from any function-calling overhead.

Basic example of empty array:

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

Output:

array(0) {
}

Now PHP 5.4, supports [] as an alternative, depending on the compiler, It's synonymous and most PHP developers use $array = [] because it makes going back and forth between JS and PHP easier.

<?php 
  
$firstempty = []; 
echo "创建第一个空数组<br>"; 
      
$second = array( ); 
echo "创建第二个空数组<br>"; 
      
$first = array( 1, 2); 
          
foreach( $first as $value ) { 
    echo "Value is $value <br>"; 
} 
          
$first[0] = "one"; 
$first[1] = "two"; 
          
foreach( $first as $value ) { 
    echo "Value is $value <br>"; 
} 
?>

Output:

创建第一个空数组 
创建第二个空数组
Value is 1 
Value is 2 
Value is one 
Value is two

Another method:

<?php 
  
$emptyArray=array(); 
  
array_push($emptyArray, "php", "中文", "网站"); 
  
print_r($emptyArray); 
?>

Output:

Array
(
    [0] => php
    [1] => 中文
    [2] => 网站
)

Recommended: "PHP Tutorial》

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