jquery如何判断from中的数组是否为空
问题描述:
也许我所表达的问题的标题不是很清楚。让我说更具体一点。我有一些HTML代码如下:jquery如何判断from中的数组是否为空
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<script src="js/jquery.js"></script>
</head>
<body>
<form action="" method="post" enctype="multipart/form-data" onsubmit="return checkpost();">
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input id="submit" type="submit" value="submit" /></p>
</form>
</body>
<script>
function checkpost() {
}
</script>
</html>
对于我的PHP编程,我要检查,如果有选择的3张图片,但我不知道如何检查,在我的js代码。 对不起,我可怜的英语使问题不太清楚,但感谢您的帮助!
答
试试这个使用jQuery,
$('#submit').on('click', function() {
pictures = $('[name="picture[]"]');
// filter the pictures element which has some values
filled = pictures.filter(function() {
return this.value.length
});
// if all images are added then return true
if (filled.length === pictures.length) {
return true;
}
alert('Please select all images');
return false;
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form action="" method="post" enctype="multipart/form-data">
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input id="submit" type="submit" value="submit" /></p>
</form>
答
You could disable the submit input until an array of values no longer contains a null;
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<script src="js/jquery"></script>
</head>
<body>
<form action="" method="post" enctype="multipart/form-data" onsubmit="return checkpost();">
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" onchange="changeHandler" />
</p>
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input name="picture[]" type="file" accept="image/gif, image/jpeg" />
</p>
<p> <input id="submit" type="submit" value="submit" disabled /></p>
</form>
</body>
<script>
var inputs = $("input[type=file]"),
submit = $("input[type=submit");
inputs.on("change", changeHandler);
function checkpost() {
// carry out action
}
function changeHandler() {
var a = [];
for(var i = 0; i < inputs.length; i++) {
a.push($(inputs[i]).val());
}
a.indexOf("") === -1 ? submit.prop("disabled", false) : submit.prop("disabled", true);
}
</script>
</html>
是否必须是明确的jQuery,或将普通的JavaScript是VAID答案吗?另外,你到目前为止尝试过什么? – gabe3886