在JQuery中比较两个相同的字符串会返回false(Comparing two identical strings in JQuery returns false)

我发现了一个有趣的问题，来自JQuery的AJAX请求的回显值，我没有回答：

我的data == "LOCKED"永远不会返回true（第13行）！

JQuery - >点击按钮时调用AJAX：

$.ajax({ url: "ajax/login_ajax_call.php", method: "POST", data: { user: usr, password: pwd } }).done(function(data){ if(data == true || data == "true"){ // -> this works with data beeing true (bool) or "true" (string) $("#form_submit").submit(); } else{ console.log(jQuery.type(data)); // -> (string) console.log(data); // -> "LOCKED" console.log(jQuery.type("LOCKED")); // -> (string) if(data == "LOCKED"){ // also tried "===" but it never returns true [...] } else{ [...] } } }); });

PHP （1） - >获取一个类返回的值（PHP（2））：

include_once("../Classes/Login_check.php"); $lih = new Login_check(); $result = $lih -> check($_POST["user"], $_POST["password"]); var_dump($result); // -> string(6) "LOCKED" echo $result;

PHP （2，“Login_check.php”）：

[...] // also tried: // $test = "LOCKED"; // var_dump($test); // -> string(6) "LOCKED" // return $test; return "LOCKED"; [...]

如果您需要进一步的信息，请告诉我！我希望有人知道导致这个问题的原因！

I discovered an interesting problem with an echoed value from an AJAX request of JQuery, which I don't have an answere for:

My data == "LOCKED" never returns true (line 13)!

JQuery -> AJAX call on button-click:

$.ajax({ url: "ajax/login_ajax_call.php", method: "POST", data: { user: usr, password: pwd } }).done(function(data){ if(data == true || data == "true"){ // -> this works with data beeing true (bool) or "true" (string) $("#form_submit").submit(); } else{ console.log(jQuery.type(data)); // -> (string) console.log(data); // -> "LOCKED" console.log(jQuery.type("LOCKED")); // -> (string) if(data == "LOCKED"){ // also tried "===" but it never returns true [...] } else{ [...] } } }); });

PHP(1) -> gets a value returned by a Class(PHP(2)):

include_once("../Classes/Login_check.php"); $lih = new Login_check(); $result = $lih -> check($_POST["user"], $_POST["password"]); var_dump($result); // -> string(6) "LOCKED" echo $result;

PHP(2, "Login_check.php"):

[...] // also tried: // $test = "LOCKED"; // var_dump($test); // -> string(6) "LOCKED" // return $test; return "LOCKED"; [...]

Tell me if you need further informations! I hope anyone know what causes this problem!