This article mainly introduces the PHP implementation of decimal, binary, octal and 16 binary conversion correlation function usage, combined with concrete instance form more detailed analysis of PHP a variety of common conversion function functions, parameters, use methods and related considerations, the need for friends can refer to the next

**1. Binary:**

**1.1. Binary Turn decimal:**

Function:`bindec(string $binary_string)`

@param $binary The _string parameter represents the binary string to be converted.

@ return returns the value such as the decimal number of the binary number represented by the $binary_string parameter.

**Function Description:**

`bindec()`

Converts a binary number to an integer type or to a float type for size.

`bindec()`

Interprets all $binary_string values as unsigned integers. This is because the Bindec () function treats its most significant bit as an order of magnitude rather than as a sign bit. "That is, the highest bit 0 or 1 is not represented by BINDEC () as + or-but by a value of 1 is 1,0 0"

**Note:** The parameter must be a string, and using other data types can cause unpredictable results.

Example:

<?php Echo bindec (' 10010 '). "\ n"; echo bindec (' 00110 '). "\ n"; echo bindec (' 1111 '). "\ n";

The above program statements will be output in turn: 18,6,15

**1.2. Binary Turn hex**

Function:`bin2hex(string $str)`

@param $str The string of ASCII characters that will be converted.

@ return returns the hexadecimal value of the converted string.

**Function Description:**

`bin2hex()`

function to convert a string of ASCII characters to a hexadecimal value. Strings can be converted back by using the pack () function.

`bin2hex()`

function conversions use byte mode, with a high four-bit word preference.

Example:

(1) `bin2hex()`

convert ' Chengdu ' to hexadecimal value:

<?php $str = Bin2Hex (' Chengdu '); Echo $str;

The above program statements will output: 6368656e676475

(2) Convert a string value from binary to 16 and back again:

<?php $str = ' Chengdu '; echo Bin2Hex ($STR). "<br/>"; Echo Pack ("h*", Bin2Hex ($STR)). "<br/>";

The above program statement output: 6368656e676475, Chengdu

**2. Eight binary:**

**2.1. Eight binary decimal:**

Function:`octdec(string $octal_string)`

@param $octal The _string parameter represents the octal string that will be converted.

@ return returns the decimal equivalent of the octal number represented by the $octal_string parameter.

**Function Description:**

`octdec()`

You can handle an integer large number, but in this case it returns a float type.

Example:

<?php Echo octdec (' 010 '). "\ n"; Echo Octdec (DECOCT (45));

The above program statements will output: 8, 45

**3. Decimal:**

3.1. Decimal Turn binary:

Function:`decbin(int $number)`

@param $number The decimal number to convert, the maximum value that can be converted is decimal 4294967295, and its decbin result is a string of 32 1.

@ return returns the binary string converted into decimal digits.

**Function Description:**

`decbin()`

The maximum decimal value that the function can convert is 4294967295, and the result is a string of 32 1.

Example:

<?php Echo decbin (10). "\ n"; Echo Decbin (50);

The above program statements will output: 1010, 110010

**3.2. Decimal goto octal:**

Function:`decoct(int $number)`

@param $number The decimal number to convert, the maximum value that can be converted is 4294967295 in decimal, and its decoct () result is "37777777777".

@ return returns a string that contains an octal representation of the given parameter of the argument.

**Function Description:**

`decoct()`

The maximum number of decimal digits the function can convert is 4294967295, and the result is "37777777777".

Example:

<?php Echo decoct (10). "\ n"; Echo decoct (50);

The above program statements will be output in turn: 12, 62

**3.3. Decimal ext. 16 binary:**

Function:`dechex(int $number)`

@param $number The decimal number that will be converted.

@ return returns a string containing the hexadecimal representation of the given parameter.

**Function Description:**

`dechex()`

The maximum number of decimal values that a function can convert is: php_int_max*2 +/-1, which is a decimal 4294967295 on a 32-bit system with `dechex()`

a result of ffffffff.

**Note:** The integer type of PHP is signed, but Dechex () can handle unsigned integers only, and negative integers are handled with no symbols.

Example:

<?php Echo Dechex (10). "\ n"; Echo Dechex (58);

The above program statements are output in turn: A, 3a

**4.16 Binary:**

**4.1.16 Binary Turn binary:**

Function: `hex2bin(string $data);`

convert hexadecimal string to binary string

@param $data data in hexadecimal notation.

@ return returns the binary string for the given data or false on failure.

**Function Description:**

If the hexadecimal string entered is an odd-numbered length or is an invalid hexadecimal string, an e_warning-level error is thrown.

Example:

<?php $hex = Hex2bin ("6368656e67206475"); Echo $hex;

The above program statements will output: Cheng du

**4.2 Hexadecimal to decimal:**

Function: `hexdec(string $hex_string);`

convert hexadecimal string to binary string

@param $hex _string The hexadecimal string that will be converted.

@ return returns the decimal number equivalent to the hexadecimal number represented by the $hex_string parameter.

**Function Description:**

`hexdec()`

Ignores any non-hexadecimal characters it encounters.

Starting with PHP 4.1.0, this function can handle an integer large number, in which case it returns a float type.

Example:

<?php Var_dump (Hexdec ("See")); Var_dump (Hexdec ("ee")); All of the above two outputs: "Int (238)" Var_dump (Hexdec ("that"));//output "int" Var_dump (Hexdec ("A0"));//output "int (160)" c5/>//can be seen by the above example: Hexdec () ignores any non-hexadecimal characters it encounters.

**5. Base_convert () function for any binary conversions:**

Function:`base_convert(string $number, int $frombase, int $tobase)`

@param $number The number that will be converted.

@param $frombase The binary of parameter #.

@param $tobase will be converted into the binary.

@ return returns a string that contains the binary representation of the symbol in the system.

**Function Description:**

The $formbase of the $number itself is specified by the system.

Both $formbase and $tobase can only be integer values between 2 and 36 (including 2 and 36).

**Note:** due to the use of internal "double" or "float" type, the operation of Base_convert () may result in loss of precision in large values.

Example:

<?php $hexadecimal = ' A37334 '; Echo Base_convert ($hexadecimal, 2); Print 101000110111001100110100 echo base_convert ($hexadecimal, +, a); Print 10711860

The above is the whole content of this article, I hope that everyone's study has helped.