RETURNS a STRING resulting from converting a number between arbitrary bases.
<?php
string base_convert ( string $num, int $from_base, int $to_base )
where,
$num = The number to convert
$from_base = The original base of the number
$to_base = The final base to convert the number
?>
| lowercase | UPPERCASE | VALUE |
| a | A | 10 |
| b | B | 11 |
| c | C | 12 |
| d | D | 13 |
| e | E | 14 |
| f | F | 15 |
| g | G | 16 |
| h | H | 17 |
| i | I | 18 |
| j | J | 19 |
| k | K | 20 |
| l | L | 21 |
| m | M | 22 |
| n | N | 23 |
| o | O | 24 |
| p | P | 25 |
| q | Q | 26 |
| r | R | 27 |
| s | S | 28 |
| t | T | 29 |
| u | U | 30 |
| v | V | 31 |
| x | X | 32 |
| w | W | 33 |
| y | Y | 34 |
| z | Z | 35 |
| ed48 | ||
EXERCISE
<?php
$dec01 = '42';
$frombase01 = 10;
$tobase01a = 2;
$tobase01b = 5;
$tobase01c = 8;
$tobase01d = 16;
$tobase01e = 36;
$dec2bin = base_convert($dec01, $frombase01, $tobase01a);
$dec2five = base_convert($dec01, $frombase01, $tobase01b);
$dec2oct = base_convert($dec01, $frombase01, $tobase01c);
$dec2hex = base_convert($dec01, $frombase01, $tobase01d);
$dec2thirtyfive = base_convert($dec01, $frombase01, $tobase01e);
echo 'base_convert("' . $dec01 . '", ' . $frombase01
. ', ' . $tobase01a . ') = (' . $dec2bin . ')<sub>'
. $tobase01a . '</sub><br><br><br>';
echo 'base_convert("' . $dec01 . '", ' . $frombase01
. ', ' . $tobase01b . ') = (' . $dec2five . ')<sub>'
. $tobase01b . '</sub><br><br><br>';
echo 'base_convert("' . $dec01 . '", ' . $frombase01
. ', ' . $tobase01c . ') = (' . $dec2oct . ')<sub>'
. $tobase01c . '</sub><br><br><br>';
echo 'base_convert("' . $dec01 . '", ' . $frombase01
. ', ' . $tobase01d . ') = (' . $dec2hex . ')<sub>'
. $tobase01d . '</sub><br><br><br>';
echo 'base_convert("' . $dec01 . '", ' . $frombase01
. ', ' . $tobase01e . ') = (' . $dec2thirtyfive . ')<sub>'
. $tobase01e . '</sub>';
?>
EXERCISE
<?php
// Run this code several times
$dec02 = mt_rand(2, 32000);
$frombase02 = 10;
$tobase02 = [ 2, 8, 16 ];
foreach($tobase02 as $base02)
{
$dec2base = base_convert($dec02, $frombase02, $base02);
echo 'base_convert("' . $dec02 . '", ' . $frombase02
. ', ' . $base02 . ') = (' . $dec2base . ')<sub>'
. $base02 . '</sub><br><br><br>';
}
?>
EXERCISE
<?php
$number03a = '3MUEOH8BI53LJ';
$frombase03a = 35;
$tobase03a = 10;
$base2dec03a = base_convert($number03a, $frombase03a, $tobase03a);
echo 'base_convert("' . $number03a . '", ' . $frombase03a
. ', ' . $tobase03a . ') = (' . $base2dec03a . ')<sub>'
. $tobase03a . '</sub><br><br><br>';
$number03ba = '3mueoh8bi53lj';
$frombase03ba = 35;
$tobase03ba = 10;
$base2dec03ba = base_convert($number03ba, $frombase03ba, $tobase03ba);
echo 'base_convert("' . $number03ba . '", ' . $frombase03ba
. ', ' . $tobase03ba . ') = (' . $base2dec03ba . ')<sub>'
. $tobase03ba . '</sub><br><br><br>';
?>
EXERCISE
<?php
$frombase = array(2,8,10,16,36);
$tobase = array(2,8,10,16,36);
$values = array(10,
27,
39,
03,
0x5F,
"10",
"27",
"39",
"5F",
"3XYZ"
);
for ($f= 0; $f < count($frombase); $f++) {
echo "<br>From base is ", $frombase[$f], "<br>";
for ($t= 0; $t < count($tobase); $t++) {
echo " to base is ", $tobase[$t], "<br>";
for ($i =0; $i < count($values); $i++){
$res = base_convert($values[$i],$frombase[$f],$tobase[$t]);
echo " value= ",
$values[$i], " res = ", $res, "<br>";
}
}
}
?>
EXERCISE
<?php
echo " Testing base_convert() : error conditions.";
// get a class
class classA
{
}
try {
base_convert(1234, 1, 10);
} catch (ValueError $e) {
echo $e->getMessage(), "<br><br>";
}
try {
base_convert(1234, 10, 37);
} catch (ValueError $e) {
echo $e->getMessage(), "<br><br>";
}
try {
base_convert(new classA(), 8, 10);
} catch (Error $e) {
echo $e->getMessage(), "<br><br>";
}
?>
EXERCISE
<?php
echo 'base_convert(\'FF\', 16, 10) = '. base_convert('FF', 16, 10) . "<br><br>";
echo 'base_convert(\'20\', 8, 10) = ' . base_convert('20', 8, 10) . "<br><br>";
echo 'base_convert(\'0xFf\', 16, 10) = ' . base_convert('0xFf', 16, 10) . "<br><br>";
echo 'base_convert(\'0FF\', 16, 10) = ' . base_convert('0FF', 16, 10) . "<br><br>";
echo 'base_convert(" 0xFF\t\n" , 16, 10) = ' . base_convert(" 0xFF\t\n" , 16, 10) . "<br><br>";
echo 'base_convert(" 0xFF\t\n" , 16, 10) = ' . base_convert(" 0xFF\t\n" , 16, 10) . "<br><br>";
echo 'base_convert("\r\nFF\t\n" , 16, 10) = ' . base_convert("\r\nFF\t\n" , 16, 10) . "<br><br>";
echo 'base_convert("0o7" , 8, 10) = ' . base_convert("0o7" , 8, 10) . "<br><br>";
echo 'base_convert("0b1010" , 2, 10) = ' . base_convert("0b1010" , 2, 10) . "<br><br>";
echo "<br><br>";
echo 'THESE SHOULD FAIL!<br><br>';
echo 'base_convert(\'fg\', 16, 10) = ' . base_convert('fg', 16, 10) . "<br><br>";
echo "base_convert('f 0xff ', 16, 10) = " . base_convert('f 0xff ', 16, 10) . "<br><br>";
echo "base_convert('1xff ', 16, 10) = " . base_convert('1xff ', 16, 10) . "<br><br>";
echo 'base_convert(chr(0), 16, 10) = ' . base_convert(chr(0), 16, 10) . "<br><br>";
echo 'base_convert("0o7" , 9, 10) = ' . base_convert("0o7" , 9, 10) . "<br><br>";
echo 'base_convert("0 0" , 9, 10) = ' . base_convert("0 0" , 9, 10) . "<br><br>";
?>
EXERCISE
<?php
echo 'PHP ' . PHP_VERSION . '<br><br>';
echo "Testing base_convert() : usage variations.";
//get an unset variable
$unset_var = 10;
unset ($unset_var);
// heredoc string
$heredoc = <<<EOT
abc
xyz
EOT;
// get a resource variable
$fp = fopen(__FILE__, "r");
$inputs = array(
// int data
/*1*/ 0,
1,
12,
-12,
2147483647,
// float data
/*6*/ 10.5,
-10.5,
1.234567e2,
1.234567E-2,
.5,
// null data
/*11*/ NULL,
null,
// boolean data
/*13*/ true,
false,
TRUE,
FALSE,
// empty data
/*17*/ "",
'',
array(),
// string data
/*20*/ "abcxyz",
'abcxyz',
$heredoc,
// undefined data
/*23*/ @$undefined_var,
// unset data
/*24*/ @$unset_var,
// resource variable
/*25*/ $fp
);
// loop through each element of
// $inputs to check the behaviour of base_convert()
$iterator = 1;
foreach($inputs as $input) {
echo "<br><br>Iteration: $iterator<br>";
try {
var_dump(base_convert($input, 10, 8));
} catch (TypeError $exception) {
echo $exception->getMessage() . "<br><br>";
}
$iterator++;
}
fclose($fp);
?>