converting a number base 10 to base 62 (a-zA-Z0-9)

Question

I have a number in base 10. Is there anyway to translate it to a base 62?

Example:

echo convert(12324324);
// returns Yg3 (fantasy example here)
         


        

Answer 1

http://us3.php.net/manual/en/function.base-convert.php#52450

 Custom
function dec2any( $num, $base=62, $index=false ) {
    if (! $base ) {
        $base = strlen( $index );
    } else if (! $index ) {
        $index = substr( "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" ,0 ,$base );
    }
    $out = "";


    // this fix partially breaks when $num=0, but fixes the $num=238328 bug
    // also seems to break (adds a leading zero) at $num=226981 through $num=238327 *shrug*
    // for ( $t = floor( log10( $num ) / log10( $base - 1 ) ); $t >= 0; $t-- ) {

    // original code:
    for ( $t = floor( log10( $num ) / log10( $base ) ); $t >= 0; $t-- ) {
        $a = floor( $num / pow( $base, $t ) );
        $out = $out . substr( $index, $a, 1 );
        $num = $num - ( $a * pow( $base, $t ) );
    }
    return $out;
}
?>

Parameters:

$num - your decimal integer

$base - base to which you wish to convert $num (leave it 0 if you are providing $index or omit if you're using the default (62))

$index - if you wish to use the default list of digits (0-1a-zA-Z), omit this option, otherwise provide a string (ex.: "zyxwvu")

 Decimal
function any2dec( $num, $base=62, $index=false ) {
    if (! $base ) {
        $base = strlen( $index );
    } else if (! $index ) {
        $index = substr( "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ", 0, $base );
    }
    $out = 0;
    $len = strlen( $num ) - 1;
    for ( $t = 0; $t <= $len; $t++ ) {
        $out = $out + strpos( $index, substr( $num, $t, 1 ) ) * pow( $base, $len - $t );
    }
    return $out;
}
?>

Parameters:

$num - your custom-based number (string) (ex.: "11011101")

$base - base with which $num was encoded (leave it 0 if you are providing $index or omit if you're using default (62))

$index - if you wish to use the default list of digits (0-1a-zA-Z), omit this option, otherwise provide a string (ex.: "abcdef")