我是 JavaScript 新手，我需要一些帮助。我有一个表单和一些 JavaScript，但在输入错误范围时添加警报框时遇到问题。我希望显示一个警报框，输入范围为 1-80，例如 81。
<script type="text/javascript">
// hide from old browsers
if (top != self) {
top.location = self.location.href
}
// end script hiding
</script>
<script type="text/javascript">
// hide from non scripting browsers
function chooseRandom(form) {
var m = parseInt(form.lower.value);
var n = parseInt(form.upper.value) - m;
var output = Math.round(Math.random() * n) + m;
form.result.value = output;
}
// Clears the form
function clearForm(form) {
form.upper.value="";
form.lower.value="";
form.upper.focus();
form.upper.select();
}
</script>
<script type="text/javascript">
// calculates range from 1 - 80
var browName = navigator.appName;
var SiteID = 1;
var ZoneID = 80;
var browDateTime = (new Date()).getTime();
</script>
最佳答案
希望这就是您正在寻找的:
<!DOCTYPE html>
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript">
function chooseRandom(form) {
var m = parseInt(form.lower.value);
var n = parseInt(form.upper.value) - m;
var output = Math.round(Math.random() * n) + m;
form.result.value = output;
}
function clearForm(formId) {
var form = document.getElementById(formId);
form.upper.value = "";
form.lower.value = "";
form.result.value = "";
form.upper.focus();
}
function chooseResult(formId) {
var form = document.getElementById(formId);
var upperVal = parseInt(form.upper.value);
var lowerVal = parseInt(form.lower.value);
if(isNaN(lowerVal) || isNaN(upperVal) || (lowerVal < 1) || (upperVal > 80) || (lowerVal >= upperVal)) {
alert("Value(s) out of range, must be 1 <= lower < upper <= 80");
clearForm(formId);
}
else {
// alert("Values ok");
chooseRandom(form);
}
}
</script>
</head>
<body>
<form id="form1" method="GET" action="">
<p>Upper:</p><input id="upper" name="upper" type="number">
<p>Lower:</p><input id="lower" name="lower" type="number">
<p>Result:</p><input id="result" name="result" type="number">
<button type="button" onclick="chooseResult('form1')">Choose result</button>
<button type="button" onclick="clearForm('form1')">Clear form</button>
<button type="submit">Submit form</button>
</form>
</body>
</html>
关于javascript - 我希望获得 1 - 80 范围内的数字，如果不在该范围内，则会出现警报框，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16106021/