php to hexadecimal

With the popularization of the Internet, our lives are increasingly closely related to the Internet, and various programming languages ​​​​also play an important role in network development. Among them, PHP, as a scripting language widely used in network development, is known and used by more and more developers. However, in actual development, we often need to use the hexadecimal conversion function, and PHP itself only provides methods for decimal, hexadecimal, octal and binary conversion, and does not provide conversion to hexadecimal. Methods. Next, let's explore how PHP implements the function of converting to hexadecimal.

Before this, we need to understand what hexadecimal is. Base 62 is a base system that converts numbers or characters into base 62. It consists of numbers and uppercase and lowercase letters, where 0-9 represents numbers, A-Z represents uppercase letters, and a-z represents lowercase letters. Hexadecimal has been widely used in fields such as short URLs and massive data storage.

We can implement the function of converting php to hexadecimal by following the following steps:

1. Define the characters contained in hexadecimal

First, we need to define The character set included in the hexadecimal system includes numbers 0-9, uppercase letters A-Z, and lowercase letters a-z, a total of 62 characters. You can use a string to store these characters, as shown below:

$chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';

2. Define the conversion function

Next, we need to define a Function that converts a decimal number into a hexadecimal number. This function needs to first perform remainder and division operations on the number, map the remainder to the 62-base character set to obtain a character, and use the quotient as the next input. Repeat this process until the quotient is 0, and the final string obtained is a hexadecimal representation. The code is as follows:

function base62_encode($number)
{

global $chars;
$base = 62;
$index = '';
do {
    $mod = $number % $base;
    $index .= $chars[$mod];
    $number = ($number - $mod) / $base;
} while ($number > 0);
return $index;

}

In this example, we set the base 62 to 62, and Store the character set in the global variable $chars. In the loop, first perform remainder and division operations on the number, map the remainder to the character set to find the corresponding character, and splice it to the end of the string $index. Then use the quotient as the next input, continue this process until the quotient is 0, and return the final string.

3. Define the inverse conversion function

Since we need to convert between 62-base and 10-base, we also need to define a function to convert 62-base number to decimal. function of number. This function needs to traverse the string from right to left, take out each character, obtain its position in the 62-base character set, multiply it by the power of 62, and add it to the result. The code is as follows:

function base62_decode($index)
{

global $chars;
$base = 62;
$length = strlen($index);
$number = 0;
for ($i = 0; $i < $length; $i++) {
    $number += strpos($chars, $index[$i]) * pow($base, $length - $i - 1);
}
return $number;

}

In this example, we also set the hexadecimal base to 62, And store the character set in the global variable $chars. In the loop, we traverse the string from right to left, take out each character, use the strpos function to get its position in the character set, then multiply it by the power of 62, and accumulate the result into $number. Finally return $number.

4. Test function

Finally, we test to see if these two functions can work properly. We can use the rand function to generate a random decimal number, then convert it to base 62, then convert it to base 10, and finally compare the two numbers to see if they are equal. The code is as follows:

$number = rand(1, 1000000);
$index = base62_encode($number);
$decode = base62_decode($index);

echo 'number: ' . $number . PHP_EOL;
echo 'index: ' . $index . PHP_EOL;
echo 'decode: ' . $decode . PHP_EOL;

Run the above code. See the randomly generated decimal number, the string converted to hexadecimal, and the number obtained after converting again to decimal.

To sum up, we have realized the function of converting decimal numbers into 62-digit numbers by defining character sets, conversion functions and reverse conversion functions, and conducting tests. It is worth noting that this conversion can only handle positive integers. If the input is a negative number or 0, the converted result will be an empty string. In actual development, it needs to be modified and adapted according to specific needs.

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