How to convert ASCII code to numerical value in php

In PHP programming, ASCII code is a very important encoding method. It is the standard encoding method used to represent characters in computer systems. When we need to process characters or operate strings in PHP, we must understand how to convert ASCII codes into numerical values ​​so that we can better complete our programming tasks.

The ASCII code table contains a total of 128 characters. These characters are represented by integers from 0 to 127. These integers are represented as a byte internally in the computer and can be directly read and processed when using characters. . ASCII characters are used in PHP to complete many regular character processing tasks, such as string conversion, character replacement, etc. Numeric values ​​are needed to represent ASCII codes, so we need to understand how to convert ASCII codes into numerical values.

The following is the PHP code method to convert ASCII code to numerical value:

function ascii_to_number($string)
{
    $length = strlen($string);
    $x = 0;
    for ($i = 0; $i < $length; $i++) {
        $x = ($x * 128) + ord($string{$i});
    }
    return $x;
}

In this code, we use the ord() function to convert characters into ASCII code, and then convert the ASCII code into numerical value , complete this process in an iterative loop. This function can accept any string as a parameter and convert each character in the string into the corresponding numerical value.

Then we can test the actual application effect of this function through the following code:

$string = "Hello World!";
$number = ascii_to_number($string);
echo "The ASCII number of '{$string}' is: {$number}";

In this test code, we use this function to convert the characters in the string "Hello World!" Convert to the corresponding ASCII code and calculate its value. Finally we use the echo statement to output the results to the screen.

Through the output of the above code, we can see that the function calculated the value corresponding to the string "Hello World!" and output it to the screen, which shows that the function successfully completed the ASCII The operation of converting code to numerical value.

Generally speaking, ASCII code is very important in PHP programming. It can improve programming efficiency and quality to a certain extent, because developers can better utilize the characteristics of ASCII code to implement various characters. Processing work. At the same time, we also need to understand how to convert ASCII codes to numerical values ​​or numbers. This conversion is particularly useful for processing characters, especially when numbers and characters are mixed, because it allows us to better convert characters into numbers. Perform numerical calculations.

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