How to send button value with form - html

Question

I have a form and ajax.
I can't send with $(form).serialize();
How do I send the button value with the form?
html:
<form action="" id="ogrenci_arama_formu">
<input type="text" id="eposta" name="eposta">
<button id="ogrenci_ara" name="ogrenci_ara" value="true" class="btn btn-info">Öğrenciyi Ara</button>
<!--<input id="ogrenci_ara" type="hidden" name="ogrenci_ara" value="true">-->
</form>
ajax:
$("#ogrenci_arama_formu").submit(function (e) {
e.preventDefault();
console.log("form: ",$(this).serialize());
$.ajax({
url: "sayfalar/ogrenci_bilgileri.php",
type: 'post',
/*dataType: 'json',*/
data: $(this).serialize()
}).done(function(data) {
$("tbody").html(data);
}).fail(function(data) {
console.log("error",data);
});
});
output:
eposta=

Answer 1

try like store button value into a variable and send with form serialize like this
JAVASCRIPT-
$("#ogrenci_arama_formu").submit(function(e) {
e.preventDefault();
var btnValue = $(this).find('#ogrenci_ara').val();
console.log("form: ", $(this).serialize()+'&ogrenci_ara='+btnValue);
$.ajax({
url: "sayfalar/ogrenci_bilgileri.php",
type: 'post',
/*dataType: 'json',*/
data: $(this).serialize()+'&ogrenci_ara='+btnValue
}).done(function(data) {
$("tbody").html(data);
}).fail(function(data) {
console.log("error", data);
});
});