如何根据特定用户输入在JavaScript中显示警报
[英]How to show an alert in JavaScript based on specific user input
问题描述
I need an alert that says "enter a digit from 0 to 9 please" when typing a letter, a comma, minus, plus, bracket, question mark etc. (only numbers can be entered). 
输入字母，逗号，减号，加号，方括号，问号等时，我需要显示“请输入0到9之间的数字”的警报（只能输入数字）。
My alert is not working, I cannot connect it. 我的警报不起作用，我无法连接它。
I am asking you for help. 我正在寻求您的帮助。
The alert should be shown after trying to enter letters, commas etc. in the table, except for numbers 尝试在表格中输入字母，逗号等后，应显示警告，数字除外
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <html> <head> <script src="http://code.jquery.com/jquery-1.9.1.js" type="text/javascript"></script> <meta charset="utf-8"> </head> <body> <script type="text/javascript"> (function($) { $.fn.average = function() { var sum = 0; this.each(function() { sum += parseFloat($(this).val()); //; }); return sum / $(this).length; } })(jQuery); $(document).ready(function() { $(":reset") }); $(document).ready(function() { $("#calc").click(function() { var s = $("input[type='number']").average(); console.debug(s); $('#result').html(s); }); $(".reset").on('click', function() { $("#result").html(" "); }) }); </script> <h1>Oblicz średnią:</h1> <form action=""> <input onkeypress="if((event.keyCode < 48 || event.keyCode > 57) && (event.keyCode != 44))return false" type="number"><br> <input onkeypress="if((event.keyCode < 48 || event.keyCode > 57) && (event.keyCode != 44))return false" type="number"><br> <input onkeypress="if((event.keyCode < 48 || event.keyCode > 57) && (event.keyCode != 44))return false" type="number"><br> <div id="result" type="reset"></div><br> <input type="button" id="calc" value="Licz"> <input type="reset" value="Reset" class="reset"> </form> <script> function setTimeout(function() {}, 10); () { confirm("Press a button!"); } </script> </body> </html>
1 个解决方案
解决方案1
0 已采纳 2018-05-29 16:29:48
Using Input type="number" with pattern="[0-9]*" allows letters in firefox as a reference. 使用输入type =“ number”和pattern =“ [0-9] *”可以将Firefox中的字母作为参考。
So with the help of regex you can prevent different input types. 因此，借助regex您可以防止使用不同的输入类型。 So on your onkeypress method use the following function: 因此，在您的onkeypress方法上使用以下功能：
<input onkeypress="preventNonNumericalInput(event)" type="number">
Then declare this function in your js file: 然后在您的js文件中声明此函数：
function preventNonNumericalInput(e) {
e = e || window.event;
var charCode = (typeof e.which == "undefined") ? e.keyCode : e.which;
var charStr = String.fromCharCode(charCode);
if (!charStr.match(/^[0-9]+$/)){
alert("Enter a digit from 0 to 9 please")
e.preventDefault();
}
}
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.