The same string is not equal

If the strings are not the same, the ip address and port are collected from a page. $ ip and $ duankou are collected and cannot be used. However, manual input can be used.
The two strings have different lengths but the encoding is the same. what should I do?
$ B is valid, $ a is invalid,

$ A = "tcp: //". $ ip. ":". $ duankou; $ B = "tcp: // 77.81.105.147: 7808"; echo $ ."
"; Echo $ B ."
"; $ Encode = mb_detect_encoding ($ a, array (" ASCII "," UTF-8 "," GB2312 "," GBK "," BIG5 ")); $ encodes = mb_detect_encoding ($ B, array ("ASCII", "UTF-8", "GB2312", "GBK", "BIG5"); echo $ encode."
"; Echo $ encodes ."
"; $ Changdu1 = strlen ($ a); $ changdu2 = strlen ($ B); echo $ changdu1 ."
"; Echo $ changdu2; if ($ a = $ B) {echo" equal ";} else {echo" not equal ";}

Output:

// Character tcp: // 77.81.105.147: 7808tcp: // 77.81.105.147: 7808 // encoded ASCIIASCII // length: 4224 // result range

Reply to discussion (solution)

Var_dump ($ a, $ B, $ encode, $ encodes );
Post result

Preferably
Echo base64_encode (serialize (array ($ a, $ B, $ encode, $ encodes )));
Post result

There are invisible empty characters in the collected data. try ip and port trim ().

Preferably
Echo base64_encode (serialize (array ($ a, $ B, $ encode, $ encodes )));
Post result

Result

YTo0OntpOjA7UzoyNDoidGNwOi8vNzcuODEuMTA1LjE0Nzo3ODA4IjtpOjE7Uzo0MjoidGNwOi8vPHRkPjc3LjgxLjEwNS4xNDc8L3RkPjo8dGQ+NzgwODwvdGQ+IjtpOjI7Uzo1OiJBU0NJSSI7aTozO1M6NToiQVNDSUkiO30=

There are invisible empty characters in the collected data. try ip and port trim ().

Trim () is over. it's still the same.

$s = 'YTo0OntpOjA7UzoyNDoidGNwOi8vNzcuODEuMTA1LjE0Nzo3ODA4IjtpOjE7Uzo0MjoidGNwOi8vPHRkPjc3LjgxLjEwNS4xNDc8L3RkPjo8dGQ+NzgwODwvdGQ+IjtpOjI7Uzo1OiJBU0NJSSI7aTozO1M6NToiQVNDSUkiO30=';$a = unserialize(base64_decode($s));var_dump($a);

array(4) {  [0]=>  string(24) "tcp://77.81.105.147:7808"  [1]=>  string(42) "tcp://77.81.105.147:7808"  [2]=>  string(5) "ASCII"  [3]=>  string(5) "ASCII"}

The reason is obvious, right?
In fact, you can view the source code of the web page in the browser.

I have neglected the problem. thank you.