How to see binary representation of variable

Question

Is there any possibility to see binary representation of variable?

what exactly do you want to see? number in base2? – vartec Apr 18 '11 at 15:33 — vartec, Apr 18 '11 at 15:33

score 10 · Accepted Answer · answered Apr 18 '11 at 15:34

10

Like so:

echo decbin(3); // 11

answered Apr 18 '11 at 15:34

Josh

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score 8 · Answer 2 · answered Aug 23 '13 at 16:29

8

Another solution:

function d2b($dec, $n = 16) {
    return str_pad(decbin($dec), $n, "0", STR_PAD_LEFT);
}

Example:

// example:
echo d2b(E_ALL);
echo d2b(E_ALL | E_STRICT);
echo d2b(0xAA55);
echo d2b(5);

Output:
0111011111111111
0111111111111111
1010101001010101
0000000000000101

answered Aug 23 '13 at 16:29

Mario Campa

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`$n = PHP_INT_SIZE * 8;` – whyer Nov 25 '20 at 14:31

score 5 · Answer 3 · answered Apr 18 '11 at 15:34

5

decbin(your_int) will return a string in binary numbers representing the same value as your_int, assuming that's what you're asking for.

answered Apr 18 '11 at 15:34

Wooble

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score 3 · Answer 4 · answered Apr 18 '11 at 15:34

<?php
/**
 *    Returns an ASCII string containing
 *    the binary representation of the input data .
**/
function str2bin($str, $mode=0) {
    $out = false;
    for($a=0; $a < strlen($str); $a++) {
        $dec = ord(substr($str,$a,1));
        $bin = '';
        for($i=7; $i>=0; $i--) {
            if ( $dec >= pow(2, $i) ) {
                $bin .= "1";
                $dec -= pow(2, $i);
            } else {
                $bin .= "0";
            }
        }
        /* Default-mode */
        if ( $mode == 0 ) $out .= $bin;
        /* Human-mode (easy to read) */
        if ( $mode == 1 ) $out .= $bin . " ";
        /* Array-mode (easy to use) */
        if ( $mode == 2 ) $out[$a] = $bin;
    }
    return $out;
}
?>

Copied from: http://php.net/manual/en/ref.strings.php

it'd be easier to replace the inner loop with decbin(), or at least use bit shifting rather than exponential functions. — Marc B, Apr 18 '11 at 15:46
yes I also noticed it. It's not mine code I just copied from the php site. — tim_a, Apr 18 '11 at 16:05

score 3 · Answer 5 · edited May 23 '17 at 12:34

Or you may use base_convert function to convert symbol codes to binary, here's a modified function:

function str2bin($str) 
{
    $out=false; 
    for($a=0; $a < strlen($str); $a++)
    {
        $dec = ord(substr($str,$a,1)); //determine symbol ASCII-code
        $bin = sprintf('%08d', base_convert($dec, 10, 2)); //convert to binary representation and add leading zeros
        $out .= $bin;
    }
    return $out;
}

It is useful to convert inet_pton() result to compare ipv6 addresses in binary format (since you cannot really convert a 128-bit ipv6 address to integer, which is 32- or 64-bit in php). You can find more on ipv6 and php here (working-with-ipv6-addresses-in-php) and here (how-to-convert-ipv6-from-binary-for-storage-in-mysql).

score 2 · Answer 6 · answered Oct 01 '13 at 06:27

2

$a = 42;
for($i = 8 * PHP_INT_SIZE - 1; $i >= 0; $i --) {
    echo ($a >> $i) & 1 ? '1' : '0';
}

answered Oct 01 '13 at 06:27

dev1

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score 1 · Answer 7 · answered Apr 18 '11 at 15:41

1

What about: <?php $binary = (binary) $string; $binary = b"binary string"; ?>

(from php.net)

answered Apr 18 '11 at 15:41

Zach Lysobey

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That doesn't show the string in binary representation, it only "converts" (or casts) a literal string into a binary string. – Pedro Cunha Apr 19 '11 at 09:47

How to see binary representation of variable

7 Answers7

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