Briefly describe how to assign values ​​to PHP arrays

This article mainly introduces the detailed explanation of the PHP array assignment method. The article introduces and explains in detail how to create an array and how to assign values ​​to the PHP array. I hope it will be helpful to everyone.

PHP arrays are quite commonly used, so I studied PHP array assignment and shared them with you here. I hope it will be useful to everyone.

The so-called array is a set of variables stored in the computer's memory. These variables can be of different types, including integers, Boolean values, strings, etc.

It can be said that an array is a small database in memory. It provides a quick way for us to access data. It can save IO or frequent access to the database to improve some performance, so about the array Some operations are also numerous.

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How to create an array in PHP, you can use the following method:

One of the methods to create an array:

<?php 
$a="abcd"; 
print($a[0]." ".$a[1]." ".$a[2]." ".$a[3]." "); 
?>

Result:

a b c d

Method 2:

<?php 
$http=array("www","helpphp","cn");  
print($http[0].".".$http[1].".".$http[2]);  
?>

Knowledge description:

1. We pass As you can see from the previous example, arrays in PHP start from the subscript (index) by default to indicate the position of the variable in the array, which means that we can use the form: $variable name [index] to access the array we created.

2. We use the array() language structure to create data. In the array, if the subscript is not explicitly specified, the index starts from 0 and increases by default. The array we created has been saved in memory, but after the data is used, we need to do some cleaning to ensure memory leaks.

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How to assign values ​​to PHP arrays?

is as follows:

$My_array=array();
$My_array[]="www" ;
$My_array[]="helpphp"; 
$My_array[]="cn";

Through the above method, I created an empty array for the variable using the array language structure, and assigned a value to $My_array in the following statement , in the previous section, we know that the array subscript (index) automatically increases from 0, which means that the following statement will output helpphp.

Print $My_array[1];

If you want to output $My_array all at once, you can use print_r($My_array).

How to destroy the array or the elements in the array. To complete the above task, just use the unset() function. It You can delete the entire array or an element in the array, as follows:

unset($My_array[0];   
unset($My_array);

Note What's interesting is that after deleting the array element, the index value will retain its original position and the index will not be readjusted. You only need to compare after deletion to find this phenomenon.

Use var_dump() to view more detailed things in the array, as follows:

Var_dump($My_array);

The above is to teach you about PHP arrays Assignment method, I hope it will inspire everyone's learning.

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