Javascript 检查输入值长度
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/12164751/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Check input value length
提问by user1609394
I have a problem with input checking. I don't want to send the request if the input length is less than 3.
我有输入检查问题。如果输入长度小于 3，我不想发送请求。
My form:
我的表格：
<form method='post' action=''>
Albūma nosaukums: # # this is the input --><input id='titleeee' type='text' name'album_title' /><br />
Bilde Nr 1: <input type='file' name='pic_nr1' /><br />
Bilde Nr 2: <input type='file' name='pic_nr2' /><br />
Bilde Nr 3: <input type='file' name='pic_nr2' /><br />
Aktīvs*:
<select>
<option>Jā</option>
<option>Nē</option>
</select>
<br />
<input Onclick='testlenght(document.getElementById("titleeee"), "Tavs albūma nosaukums ir pa īsu!", "3")' type='submit' value='Pievienot' />
</form>
回答by dm03514
You can add a form onsubmit handler, something like:
您可以添加表单提交处理程序，例如：
<form onsubmit="return validate();">
</form>
<script>function validate() {
// check if input is bigger than 3
var value = document.getElementById('titleeee').value;
if (value.length < 3) {
return false; // keep form from submitting
}
// else form is good let it submit, of course you will
// probably want to alert the user WHAT went wrong.
return true;
}</script>
回答by ogelacinyc
<input type='text' minlength=3 /><br />
<input type='text' minlength=3 /><br />
if browser supports html5,
如果浏览器支持 html5，
it will automatical be validate attributes(minlength) in tag
它将自动验证标签中的属性（最小长度）
but Safari(iOS) doesn't working
但 Safari(iOS) 不起作用
