检查输入文件是否为空 jquery
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check if input file filed is empty jquery
提问by hyperrjas
I have a form with a file input and I want to check if it is empty when the form is submitted.
我有一个带有文件输入的表单，我想在提交表单时检查它是否为空。
I have this code:
我有这个代码：
$('form#new_comment').submit(function(e) {
var $this = $(this);
var $input = $this.find('input').val();
if($($input == '')) {
alert ("you must choose a image");
return false;
e.preventDefault();
}
});
But it always says you must choose a image, even when I have chosen an image.
但它总是说you must choose a image，即使我选择了一个图像。
Where is the problem?
问题出在哪儿？
回答by Sarfraz
Change:
改变：
if($($input == '')) {
To:
到：
if($input == '') {
Since it is simple variable that holds text, you don't need to use jQuery function over it again.
由于它是保存文本的简单变量，因此您无需再次使用 jQuery 函数。
