来自MySQL的数据时，Typeahead不提供来自PHP文件的响应

如何解决来自MySQL的数据时，Typeahead不提供来自PHP文件的响应

我正在尝试从PHP文件（JSON数据）获取自动完成数据（提前输入）。但是，仅当我复制粘贴JSON数据并从PHP文件中回显它时，此方法才有效。如果我使用字符串生成器或array_push（）函数生成完全相同的JSON数据，则此方法无效。 数据非常庞大，我比较了两个PHP文件的输出；完全一样。

工作代码 回声json_encode（array（“ Volvo”，“ BMW”，“ Toyota”））; 该PHP文件的输出：[“ Acura”，“ Audi”，“ BMW”]

不工作 来自MysqL的数据回显 此PHP文件的输出：[“ Acura”，“ Audi”，“ BMW”]

JAVASCRIPT

$.typeahead({
input: '.js-typeahead-car_v1',minLength: 1,order: "asc",offset: true,hint: true,source: {
    car: {
        data: ["My first added brand","M1 added brand at start"],ajax: {
            type: "POST",url: "car_v1.PHP",data: {
                myKey: "myValue"
            }
        }
    }
},callback: {
    onClick: function (node,a,item,event) {

        console.log(node)
        console.log(a)
        console.log(item)
        console.log(event)

        console.log('onClick function triggered');

    },onSubmit: function (node,form,event) {

        console.log(node)
        console.log(form)
        console.log(item)
        console.log(event)

        console.log('onSubmit override function triggered');

    }
}
})

HTML

<form id="form-car_v1" name="form-car_v1">
<div class="typeahead__container">
    <div class="typeahead__field">
        <div class="typeahead__query">
            <input class="js-typeahead-car_v1" name="car_v1[query]" placeholder="Search" autocomplete="off">
        </div>
        <div class="typeahead__button">
            <button type="submit">
                <i class="typeahead__search-icon"></i>
            </button>
        </div>
    </div>
</div>

Car_V1.PHP

header('Content-Type: application/json');

echo json_encode(
array(
    "Acura","Audi","BMW","Buick","Cadillac","Chevrolet","Dodge","Chrysler","Ford","GMC","Hyunday","Infinity","Jaguar","Jeep","Kia Motors","Land Rover","Lexus","Lincoln","Mazda","Mercedes-benz","Mitsubishi","Nissan","Pontiac","Porsche","Saab","Saturn","Scion","Subaru","Suzuki","Toyota","Honda","Hummer","Mercury","Mini","Volkswagen","Volvo"
  )
 );