Develop Reference

Two arguments from one input. JavaScript

Im doing JS exercises. The task is:
Write a JavaScript program to check whether two given integer values are in the range 50..99 (inclusive). Return true if either of them are in the said range.
Task is easy, I took two numbers from two inputs.
Is there possibility to take two numbers from only one input?
and start function like this:
function task28(fnum, snum){}
Below is mine solution with two inputs.
<input type="text" id="task28a" class="form-control" placeholder="write number" aria-label=""
aria-describedby="basic-addon2">
<input type="text" id="task28b" class="form-control" placeholder="write number" aria-label=""
aria-describedby="basic-addon2">
</br>
<button type="button" class="btn btn-dark btn-sm" onclick="task28()">Check</button>
<p class="answer" id="task28ans"></p>
<script>
function task28() {
let fnum = document.getElementById("task28a").value;
let snum = document.getElementById("task28b").value;
if (
(fnum >= 50 && fnum <= 99) && (snum >= 50 && snum <= 99)
) {
document.getElementById("task28ans").innerHTML = "true";
} else {
document.getElementById("task28ans").innerHTML = "false";
}
}
</script>

I'd suggest you to use a form and run a function on submit.
This can also simplify retrieve your values
function DoSubmit(){
var a = document.myform.myinput.value;
var b = document.myform.message.value;
console.log(a,b)
}
<form name="myform" onsubmit="DoSubmit();">
<input type="text" name="myinput" value="" />
<input type="text" name="message" value="" />
<input type="submit" name="submit" />
</form>

Check below code....
function task28() {
let tempVar = document.getElementById("task28a").value;
let splitArray = tempVar.split(" ");
if(splitArray.length == 2)
{
let fnum = parseInt(splitArray[0]);
let snum = parseInt(splitArray[1]);
if ((fnum >= 50 && fnum <= 99) && (snum >= 50 && snum <= 99)) {
document.getElementById("task28ans").innerHTML = "true";
} else {
document.getElementById("task28ans").innerHTML = "false";
}
}
}
<input type="text" id="task28a" class="form-control" placeholder="Enter number" aria-label="" aria-describedby="basic-addon2">
</br>
<button type="button" class="btn btn-dark btn-sm" onclick="task28()">Check</button>
<p class="answer" id="task28ans"></p>

button Function onclick not display in text filed

I'm writing a code that display content in text field on button submit click, but the code below is not working
<script>
function myFunction() {
var x = document.getElementById("cost").value;
if (document.getElementById("cost").value;) {
var netprofit = x-(16/100*x);
document.getElementById("net").value = +netprofit;
else if (document.getElementById("cost").value;) {
var commission = netprofit * 35/100;
document.getElementById("comm").value = +commission;
}
}
}
</script>
<form action="" method="POST">
<input type="text" id="cost" placeholder="kindly enter the cost value of project"><br><br>
<input type="text" name="" id="net" readonly="readonly"><br><br>
<input type="text" name="" id="comm" readonly="readonly"><br><br>
<input type="submit" value="Calculate" onclick="myFunction()">
</form>
I expect result to display in an input text onClicking button

As Harpel pointed out, you have to prevent the form from submitting. This is default behavior for forms that contain a input of type submit. I'd also suggest reorganizing your code a bit (vars for each input you selecting, etc). Something like the below:
<script>
function myFunction(event) {
event.preventDefault();
var costInput = document.getElementById("cost");
var netInput = document.getElementById("net");
var commInput = document.getElementById("comm");
if (costInput.value) {
var netprofit = costInput.value - (16/100 * costInput.value);
netInput.value = netprofit;
} else if (costInput.value) {
var commission = netprofit * 35/100;
commInput.value = commission;
}
}
</script>
<form action="" method="POST">
<input type="text" id="cost" placeholder="kindly enter the cost value of project"><br><br>
<input type="text" name="" id="net" readonly="readonly"><br><br>
<input type="text" name="" id="comm" readonly="readonly"><br><br>
<input type="submit" value="Calculate" onclick="myFunction(event)">
</form>
One additional thing; I'm not sure what the if statement is supposed to be checking, as it seems to be checking the same condition. If that's the case, you can just place both calculations for the input values into one if check like:
if (costInput.value) {
var netprofit = costInput.value - (16/100 * costInput.value);
netInput.value = netprofit;
var commission = netprofit * 35/100;
commInput.value = commission;
}

Your input type is submit. So it will always submit form and reload the page. You can do in function like
"return false" from your function,
event.preventDefault() add in your function //it will avoid the default behavior (in your case submit form).
Or use button in your HTML in place of ("input" with type "submit").
Here is working snippet, but i don't know why you are writing same condition in "if" and "else if"
function myFunction(e) {
e.preventDefault();
var cost = document.getElementById("cost").value;
if (cost) {
cost = +cost;
var netprofit = cost - (16 / 100 * cost);
var commission = netprofit * 35 / 100;
document.getElementById("net").value = +netprofit;
document.getElementById("comm").value = +commission;
}
}
<form action="" method="POST">
<input type="text" id="cost" placeholder="kindly enter the cost value of project"><br><br>
<input type="text" name="" id="net" readonly="readonly"><br><br>
<input type="text" name="" id="comm" readonly="readonly"><br><br>
<input type="submit" value="Calculate" onclick='myFunction(event)'>
</form>

<form action="" method="POST">
<input type="text" id="cost" placeholder="kindly enter the cost value of project"><br><br>
<input type="text" name="" id="net" readonly="readonly"><br><br>
<input type="text" name="" id="comm" readonly="readonly"><br><br>
<input type="button" value="Calculate" onclick="myFunction()">
</form>
<script>
function myFunction() {
var x = document.getElementById("cost").value;
if (document.getElementById("cost").value) {
var netprofit = x - (16 / 100 * x);
document.getElementById("net").value = +netprofit;
}
else if (document.getElementById("cost").value) {
var commission = netprofit * 35 / 100;
document.getElementById("comm").value = +commission;
}
}
</script>
Output

Dynamic form validation and disable submit button

My form is loaded with different input fields like radio button , text field ,numeric field which are generated dynamically while iterating through a list.
<c:forEach var="Item" items="${listBean.nameList}" varStatus="status">
<input type="number"name="nameList<c:outvalue='[${status.index}]'/>.initialWeight" onchange="checkOnChange(this,'<c:out value='${Item.personId}'/>','<c:out value='${Item.minWeight}'/>','<c:out value='${Item.maxWeight}'/>','<c:out value='[${status.index}]'/>')">
<br><br>
<input type="number" name="nameList<c:out value='[${status.index}]'/>.finalWeight" onchange="checkOnChange(this,'<c:out value='${Item.personId}'/>','<c:out value='${Item.minWeight}'/>','<c:out value='${Item.maxWeight}'/>','<c:out value='[${status.index}]'/>')">
<br><br>
<input type="text" class="formtext" name="nameList<c:out value='[${status.index}]'/>.Reason" id ="reason<c:out value='[${status.index}]'/>" value="" maxlength="255" >
<br><br>
<input type="submit" value="submit" id="submit" />
</c:forEach>
The numeric fields will be validated against minimum and maximum values.if any of the numeric fields fails in the validation , submit button needs to be disabled .
JSFIDDLE
Any ways to achieve this using jquery or javascript?
Thanks for your valuable time and suggestions

Give IDs to your inputs and then use jQuery's .change() function.
Example:
HTML
<input id="test" type="number"/>
<input id="test2" type="number"/>
<input id="submit" type="submit" value="Submit"/>
JS
var testVal = $('#test'),
testVal2 = $('#test2'),
submit = $('#submit'),
minVal = 22,
maxVal = 33;
testVal.change(function() {
if((testVal.val() > maxVal || testVal.val() < minVal) ||
(testVal2.val() > maxVal || testVal.val() < minVal)) {
submit.prop('disabled', true);
} else {
submit.prop('disabled', false);
}
});
jsfiddle

So, you could do something like below.
var flag = true;
if (nameVal > maxVal) {
alert(id + ' Enter the reason before proceeding');
//var reason = nameList[index].Reason;
document.getElementbyId("reason" + index).focus();
flag = false;
}
if (itemVal < minVal) {
alert(id + ' Enter the reason before proceeding');
//var reason = nameList[index].Reason;
document.getElementbyId("reason" + index).focus();
flag = false;
}
document.getElementById("submit").disabled = !flag;
return flag;

Validate Numbers Javascript

I have written the code so far and came up with this. I have to
Make sure the user input numbers into the text boxes and I was given errors using the Xhtml format, one, the '&&' sign gave me errors and due to online help, I was told I needed to use //
As I student learning Javascript I have no idea what this is or means, but as I placed it there, I was given more errors and my code crashed up after the javascript was added.
Thanks for the help in advance
<head>
<script type = 'text/javascript'>
// <![CDATA[
$('#submit').click(function(){
validateRange();
validateRa();
})
function validateRange() {
var txtVal = document.getElementById("CustomerID").value;
var txtVal1=parseInt(txtVal);
if (txtVal1 >= 3000 && txtVal1 <= 3999) {
return true;
}
else {
alert('Please enter a number between 3000-3999');
return false;
}
}
function validateRa() {
var txtVal1 = document.getElementById("AcctNo").value;
var txtVal2=parseInt(txtVal1);
if (txtVal2 >= 90000 && txtVal2 <= 99999) {
return true;
}
else {
alert('Please enter a number between 90000-99999');
return false;
}
}
// ]]
</script>
<title>Account Lookup</title>
</head>
<body>
<h1> Please Provide Your Information</h1>
<p><input type="text" id="AcctNo" value="Account Number"/></p>
<p><input type="text" id="CustomerID" value="CustomerID" onchange="validateRange()"/></p>
<p><input type="text" name="Type" value="Account Type" onchange="validateRange()"/></p>
<p><input type="text" name="balance" value="Balance"/></p>
<p class="submit" />
<input type="submit" name="commit" value="Submit" id="submit" /><button type="reset" value="Clear">Clear</button></p>
</body>
</html>

EDITED
try using this:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
$('#submit').click(function(){
validateRange();
validateRa();
});
});
function validateRange() {
var txtVal = document.getElementById("CustomerID").value;
var txtVal1=parseInt(txtVal);
if (txtVal1 >= 3000 && txtVal1 <= 3999) {
return true;
}
else {
alert('Please enter a number between 3000-3999');
return false;
}
}
function validateRa() {
var txtVal1 = document.getElementById("AcctNo").value;
var txtVal2=parseInt(txtVal1);
if (txtVal2 >= 90000 && txtVal2 <= 99999) {
return true;
}
else {
alert('Please enter a number between 90000-99999');
return false;
}
}
</script>
<html>
<title>Account Lookup</title>
<body>
<h1> Please Provide Your Information</h1>
<p><input type="text" id="AcctNo" value="Account Number"/></p>
<p><input type="text" id="CustomerID" value="CustomerID" onchange="validateRange()"/></p>
<p><input type="text" name="Type" value="Account Type" onchange="validateRange()"/></p>
<p><input type="text" name="balance" value="Balance" /></p>
<p class="submit" />
<input type="submit" name="commit" value="Submit" id="submit" /><button type="reset" value="Clear">Clear</button></p>
</body>
</html>

BTW the function validateRa missing the closing curly braces you need to add } before // ]]
function validateRa() {
var txtVal1 = document.getElementById("AcctNo").value;
var txtVal2=parseInt(txtVal1);
if (txtVal2 >= 90000 && txtVal2 <= 99999) {
return true;
}
else {
alert('Please enter a number between 90000-99999');
return false;
}
} //<= this is missing in your code
// ]]

Checking the value while typing in textbox

If say i am having a textbox input and a integer value A then how to check at time of typing the data itself that the value entered in textbox does not exceed A.
Textbox :
<input type="textbox" name="mynumber">
My script :
(According to answer by Felix)
<script type="text/javascript">
<%int n=(Integer)request.getAttribute("n");%>
var A=<%=n%>;
$('input[name^=txtDynamic_]').keyup(function () {
if (+this.value > A) {
$(this).next().html('Greater than Total shares');
flag=1;
}
else{
$(this).next().html('');
}
});
</script>
FORM :
<FORM METHOD=POST ACTION="stegnographyonshares" enctype="multipart/form-data">
<c:forEach var="i" begin="1" end="${myK}">
Enter The ${i} share number: <input type="text" name="txtDynamic_${i}" id="txtDynamic_${i}" /><span></span>
<br />
<br>
</br>
</c:forEach>
<br></br>
<INPUT TYPE="file" NAME="file" value="file">
<br></br>
<INPUT TYPE="submit" value="SAVE">
</form>
Whats problem in this ? the script code is not running and not printing the error message.Please help

You can use .keyup() event:
$('input[name=mynumber]').keyup(function() {
if(this.value.length > A) {
console.log('Toal characters exceed A')
}
});
Fiddle Demo
Based on your comment, you can do:
$('input[name=mynumber]').keyup(function() {
if(+this.value > A) {
console.log('Number exceed A');
}
});
Fiddle Demo

//length of text
var Count = 10;
//set id of your input mynumber
$("#mynumber").keyup(function(){
if($(this).val().length() > Count) {
$(this).val().subString(0,Count);
}
});

Do this:
var A = 10;
$('[name="mynumber"]').keyup(function () {
if (parseInt($(this).val(), 10) > A) {
alert("More than A");
} else {
alert("Less than A");
}
});
Demo

Can even be done using HTML5 output tag
<form oninput="x.value = parseInt(a.value) > 10 ? 'Greater than 10' : 'Less than 10' ">
<input type="range" id="a" value="">
<output name="x" for="a"></output>
</form>
Fiddle
Reference