PHP Functions Detailed explanation of decimal, binary, octal and hexadecimal conversion functions_PHP Tutorial

1. Description of decimal system conversion function
1. Decimal to binary decbin() function, the following example

echo decbin(12); //Output 1100
echo decbin(26); //Output 11010
decbin
(PHP 3, PHP 4, PHP 5)
decbin -- Convert decimal to binary
Description
string decbin ( int number )
Returns a string containing the binary representation of the given number parameter. The maximum value that can be converted is 4294967295 in decimal, which results in a string of 32 ones.

2, decimal to octal decoct() function

echo decoct(15); //Output 17
echo decoct(264); //Output 410
decoct
(PHP 3, PHP 4, PHP 5)
decoct -- Convert decimal to octal
Description
string decoct ( int number )
Returns a string containing the octal number of the given number parameter express. The maximum value that can be converted is 4294967295 in decimal, which results in "37777777777".

3, decimal to hexadecimal dechex() function

echo dechex(10); //Output a
echo dechex(47); //Output 2f
dechex
(PHP 3, PHP 4, PHP 5)
dechex -- Convert decimal to hexadecimal
Description
string dechex ( int number )
Returns a string containing The hexadecimal representation of the given number argument. The maximum value that can be converted is 4294967295 in decimal, which results in "ffffffff".

2. Binary system conversion function description
1. Binary to hexadecimal system bin2hex() function

$binary = "11111001";
$hex = dechex(bindec($binary));
echo $hex;//Output f9
bin2hex
(PHP 3 >= 3.0.9, PHP 4, PHP 5)
bin2hex -- Convert binary data to hexadecimal representation
Description
string bin2hex ( string str )
Returns an ASCII string, which is the hexadecimal representation of parameter str. Conversion uses byte mode, with the high nibble taking precedence.

2, binary to decimal conversion bindec() function

echo bindec('110011'); //Output 51
echo bindec('000110011' ); //Output 51
echo bindec('111'); //Output 7
bindec
(PHP 3, PHP 4, PHP 5)
bindec -- Binary to decimal conversion
Description
number bindec (string binary_string)
Returns the decimal equivalent of the binary number represented by the binary_string parameter.
bindec() Converts a binary number to an integer. The largest number that can be converted is 31 digits, or 2147483647 in decimal. Starting with PHP 4.1.0, this function can handle large values, in which case it returns a float type.

Three, octal system conversion function description
Octal to decimal octdec() function

echo octdec('77'); //Output 63
echo octdec(decoct(45)); //Output 45
octdec
(PHP 3, PHP 4, PHP 5)
octdec -- Convert octal to decimal
Instructions
number octdec (string octal_string)
Returns the decimal equivalent of the octal number represented by the octal_string parameter. The largest value that can be converted is 17777777777 or 2147483647 in decimal. Starting with PHP 4.1.0, this function can handle large numbers, in which case it returns a float type.

4. Description of hexadecimal conversion function
Hexadecimal to decimal hexdec() function

var_dump(hexdec("See" ));
var_dump(hexdec("ee"));
// both print "int(238)"

var_dump(hexdec("that")); // print "int (10)"
var_dump(hexdec("a0")); // print "int(160)"
hexdec
(PHP 3, PHP 4, PHP 5)
hexdec -- ten Convert hexadecimal to decimal
Description
number hexdec ( string hex_string )
Returns the decimal number equivalent to the hexadecimal number represented by the hex_string parameter. hexdec() Converts a hexadecimal string to a decimal number. The maximum value that can be converted is 7ffffffff, which is 2147483647 in decimal. Starting with PHP 4.1.0, this function can handle large numbers, in which case it returns a float type.
hexdec() Replaces all non-hexadecimal characters encountered with 0. This way, all zeros on the left are ignored, but zeros on the right are included in the value.

Five, arbitrary base_convert() function

$hexadecimal = 'A37334';
echo base_convert($hexadecimal, 16, 2);/ /output 101000110111001100110100
base_convert
(PHP 3 >= 3.0.6, PHP 4, PHP 5)

base_convert -- Convert numbers between arbitrary bases
Description
string base_convert (string number, int frombase, int tobase)
Returns a string containing the representation of number in tobase base. The base of number itself is specified by frombase. Both frombase and tobase can only be between 2 and 36 (inclusive). Numbers above decimal are represented by the letters a-z, such as a for 10, b for 11, and z for 35.

Here we mainly organize PHP hexadecimal conversion functions to facilitate development and search. Please refer to the PHP manual for relevant specific function descriptions. Please pay attention to the next issue of the Chinese character encoding research series.

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