How to encode a string into a unicode sequence?

Question

PHP

I ran into a problem that I can't solve. PHP programming language.
You need to encode a string into a Unicode sequence.
There is a line with value

"W+I4zLZyeJDAhQMe33tYRcXC+Falj9baMfjJw5yOijaPNHDYcnNlRlTGm3rvA6cn2hXMmW4ZKEyTphwzNMQlOlnNiCHK2LLpJLgXK6JHKuTYeParwqCud5Vn2dZXpxctrQf8OkbCqF12u0GcBR2or2HFBrEV13Jd5YAX4bRbUBk="

I need it to be encoded like this

"\u0057\u002b\u0049\u0034\u007a\u004c\u005a\u0079\u0065\u004a\u0044\u0041\u0068\u0051\u004d\u0065\u0033\u0033\u0074\u0059\u0052\u0063\u0058\u0043\u002b\u0046\u0061\u006c\u006a\u0039\u0062\u0061\u004d\u0066\u006a\u004a\u0077\u0035\u0079\u004f\u0069\u006a\u0061\u0050\u004e\u0048\u0044\u0059\u0063\u006e\u004e\u006c\u0052\u006c\u0054\u0047\u006d\u0033\u0072\u0076\u0041\u0036\u0063\u006e\u0032\u0068\u0058\u004d\u006d\u0057\u0034\u005a\u004b\u0045\u0079\u0054\u0070\u0068\u0077\u007a\u004e\u004d\u0051\u006c\u004f\u006c\u006e\u004e\u0069\u0043\u0048\u004b\u0032\u004c\u004c\u0070\u004a\u004c\u0067\u0058\u004b\u0036\u004a\u0048\u004b\u0075\u0054\u0059\u0065\u0050\u0061\u0072\u0077\u0071\u0043\u0075\u0064\u0035\u0056\u006e\u0032\u0064\u005a\u0058\u0070\u0078\u0063\u0074\u0072\u0051\u0066\u0038\u004f\u006b\u0062\u0043\u0071\u0046\u0031\u0032\u0075\u0030\u0047\u0063\u0042\u0052\u0032\u006f\u0072\u0032\u0048\u0046\u0042\u0072\u0045\u0056\u0031\u0033\u004a\u0064\u0035\u0059\u0041\u0058\u0034\u0062\u0052\u0062\u0055\u0042\u006b\u003d"

In this example, I coded via C# with the following code

var myString = "W+I4zLZyeJDAhQMe33tYRcXC+Falj9baMfjJw5yOijaPNHDYcnNlRlTGm3rvA6cn2hXMmW4ZKEyTphwzNMQlOlnNiCHK2LLpJLgXK6JHKuTYeParwqCud5Vn2dZXpxctrQf8OkbCqF12u0GcBR2or2HFBrEV13Jd5YAX4bRbUBk=";
var unicodeString = string.Join("", myString.Select(c => "\\u" + ((int)c).ToString("x4")));
return unicodeString;

But here's how to do the same in PHP, I'll never know.
Help me please!

Answer 1

If you are sure that only a-zA-Z0-9-=+- (similar to base64) will be in the input, then you can simplify and not re-encode, like this:

$uncomingString = 'W+I4zLZyeJDAhQMe33tYRcXC+Falj9baMfjJw5yOijaPNHDYcnNlRlTGm3rvA6cn2hXMmW4ZKEyTphwzNMQlOlnNiCHK2LLpJLgXK6JHKuTYeParwqCud5Vn2dZXpxctrQf8OkbCqF12u0GcBR2or2HFBrEV13Jd5YAX4bRbUBk=';


function forceUnicode( $str = '' )
{
  $result = '';

  for( $i=0,$length=strlen($str); $i<$length; $i++)
  {
    $result .= "\\u".str_pad(bin2hex($str[$i]), 4, '0', STR_PAD_LEFT);
  }

  return $result;
}

echo forceUnicode($uncomingString);

/*
Выведет: 
\u0057\u002b\u0049\u0034\u007a\u004c\u005a\u0079\u0065\u004a\u0044\u0041\u0068\u0051\u004d\u0065\u0033\u0033\u0074\u0059\u0052\u0063\u0058\u0043\u002b\u0046\u0061\u006c\u006a\u0039\u0062\u0061\u004d\u0066\u006a\u004a\u0077\u0035\u0079\u004f\u0069\u006a\u0061\u0050\u004e\u0048\u0044\u0059\u0063\u006e\u004e\u006c\u0052\u006c\u0054\u0047\u006d\u0033\u0072\u0076\u0041\u0036\u0063\u006e\u0032\u0068\u0058\u004d\u006d\u0057\u0034\u005a\u004b\u0045\u0079\u0054\u0070\u0068\u0077\u007a\u004e\u004d\u0051\u006c\u004f\u006c\u006e\u004e\u0069\u0043\u0048\u004b\u0032\u004c\u004c\u0070\u004a\u004c\u0067\u0058\u004b\u0036\u004a\u0048\u004b\u0075\u0054\u0059\u0065\u0050\u0061\u0072\u0077\u0071\u0043\u0075\u0064\u0035\u0056\u006e\u0032\u0064\u005a\u0058\u0070\u0078\u0063\u0074\u0072\u0051\u0066\u0038\u004f\u006b\u0062\u0043\u0071\u0046\u0031\u0032\u0075\u0030\u0047\u0063\u0042\u0052\u0032\u006f\u0072\u0032\u0048\u0046\u0042\u0072\u0045\u0056\u0031\u0033\u004a\u0064\u0035\u0059\u0041\u0058\u0034\u0062\u0052\u0062\u0055\u0042\u006b\u003d
*/

For your specific example, it gives the same result as required, but you need to test it on different data, of course - you could have adjusted

Answer 2

For the Cyrillic alphabet, this crutch definitely works.

echo json_encode('Мама мыла раму');
// "\u041c\u0430\u043c\u0430 \u043c\u044b\u043b\u0430 \u0440\u0430\u043c\u0443"

Now let's look for something suitable for all characters.