如何在 PHP 中声明 jquery 传递的值

Question

所以我需要声明我在 php 中用 ajax 传递的值，因为当我使用例如 if(!empty($_POST["fsearch"])) 时它什么也没显示，当我放$fsearch=$_POST['fsearch'];时，它给了我未定义的索引错误。我在jquery中有变量search_term，它将值传递给php中的"fsearch"（这也是我的输入字段的名称）。我不知道如何声明这个从Jquery到PHP的值。有代码：

jQuery(document).ready(function ($) {
	$("#food_search").keyup(function(event){
        var search_term =$(this).val();
		console.log(search_term);
        $.ajax({
	        type:"POST",
	        url:"/Food-Search",
	        data:{fsearch:search_term},
	        success:function(res){
		        $("#food_search_result").html(res);
		        console.log(res);
	        },
	        error: function (xhr, ajaxOptions, thrownError) {
                alert(xhr.status);
                alert(xhr.responseText);
                alert(thrownError);
            }
       });
	});
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!----------------------------------------------------------------
                            HTML
----------------------------------------------------------------->
<form method="POST">
    <p>Търсене на храни: <input type="text" name="fsearch" id="food_search"></p>
</form>
<!----------------------------------------------------------------
                            PHP
----------------------------------------------------------------->
<?php
if(!empty($_POST["fsearch"])) { 
    echo "True";
} else {
    echo "False";
}
?>

所以我需要将"fsearch"定义为来自jquery的值。并检查名称为"fsearch"的输入字段是否为空。感谢您的所有建议！

Answer 1

尝试这样做。

jQuery(document).ready(function ($) {
    $("#food_search").on('blur',function(){ //blur event ...triggres when input field is unfoused
        var search_term =$(this).val();
        console.log(search_term);
$.ajax({
    type:"POST",
    url:"/Food-Search.php",//if you are not using .htaccess or routing give file name with .php extension
    data:{fsearch:search_term},
    success:function(res){
        $("#food_search_result").html(res);
        console.log(res);
    },
    error: function (xhr, ajaxOptions, thrownError) {
           alert(xhr.status);
           alert(xhr.responseText);
           alert(thrownError);
       }
       });
    });
});