I have an html page that uses a javascript as a statistical calculator, it just needs to print the results into the text boxes i have displayed, but when i hit my submit button, the screen displays the mean value for a split second. no other fields work or stay.
My html file is as follows:
<!DOCTYPE html>
<html>
<head>
<meta charset=UTF-8>
<script src="script.js"></script>
<title>Script Calculator</title>
</head>
<body class="calculator">
<h2 class="stats">Statistical Calculator</h2>
<p> Enter 5-20 values within 0-100 inside the box below.<br>
Each value should be separated by one space.
</p>
<form>
<textarea id="numbers" name="numberarea" rows="4" cols="40"></textarea> <br>
<br>
<input type="submit" id="subbutton" onclick="performStatistics()"
value="Submit">
<input type="reset">
<br><br>
Max: <input type="text" id ="maxnum" name="max" readonly>
<br>
Min: <input type="text" id="minnum" name="min" readonly>
<br>
Mean: <input type="text" id="meannum" name="mean" readonly>
<br>
Median: <input type="text" id="mednum" name="med" readonly>
<br>
Mode: <input type="text" id="modenum" name="mode" readonly>
<br>
Standard Deviation: <input type="text" id="stddev" name="std" readonly>
<br>
Sum: <input type="text" id="sumnum" name="sum" readonly>
<br>
Variance: <input type="text" id="varinum" name="vari" readonly>
<br>
</form>
<hr>
ePortfolio
</body>
</html>
My javascript is as follows:
function performStatistics() {
var newarray = document.getElementById("numbers").value;
var array = newarray.split(" ");
for (var i = 0; i < array.length; i++) {
if (array[i] < 0 || array[i] > 100) {
alert("Enter positive values from 0-100")
return false;
}
}
if (array.length < 5 || array.length > 20) {
alert("Enter at least 5 values & no more than 20");
return false;
}
document.getElementById("meannum").value = calcMean(array);
document.getElementById("mednum").value = calcMedian(array);
document.getElementById("modenum").value = calcMode(array);
document.getElementById("stddev").value = calcStdDev(array);
document.getElementById("sumnum").value = calcSum(array);
document.getElementById("varinum").value = calcVariance(array);
document.getElementById("maxnum").value = findMax(array);
document.getElementById("minnum").value = findMin(array);
return false;
}
function calcMean(array) {
return calcSum(array) / array.length;
}
function calcMedian(array) {
var med = 0;
var arraylen = array.length;
arraylen.sort();
if (arraylen % 2 === 0) {
med = (array[arraylen / 2 - 1] + array[arraylen / 2]) / 2;
//takes average of an even array
} else {
med = array[(arraylen - 1) / 2];
//takes middle value of odd array
}
return med;
}
function calcMode(array) {
var mode = [];
var counter = [];
var i;
var holder;
var maxfreq = 0;
for (i = 0; i < array.length; i += 1) {
holder = array[i];
counter[array] = (counter[holder] || 0) + 1
if (counter[holder] > maxfreq) {
maxfreq = counter[holder];
}
}
for (i in counter)
if (counter.hasOwnProperty(i)) {
//returns boolean value^
if (counter[i] === maxfreq) {
mode.push(Number(i));
//pushes value into (end of) array
}
}
return mode;
}
function calcStdDev(array) {
return Math.sqrt(calcVariance(array)).toFixed(2);
}
function calcSum(array) {
var sum = 0;
for (var i = 0; i < array.length; i++) {
sum += Number(array[i]);
}
return sum.toFixed(2);
}
function calcVariance(array) {
var avg = calcMean(array);
var newarray = [];
var vari;
for (i = 0; i < array.length; i++) {
newarray[i] = (array[i] - avg) * (array[i] - avg);
}
vari = calcSum(newarray) / newarray.length;
return vari.toFixed(2);
}
function findMax(array) {
var newarray = array;
var maxnum = Math.max(newarray);
return maxnum;
}
function findMin(array) {
var newarray = array;
var minnum = Math.min(newarray)
return minnum;
}
You need to prevent the submit button from submitting the form.
window.onload=function(){
document.getElementById('subbutton').addEventListener('click', function(ev){
ev.preventDefault(); // prevent the page submit
});
}
You can remove the onclick from the HTML, and add this to your script:
// When the DOM (HTML) is ready
addEventListener('DOMContentLoaded', function() {
// When the form gets submitted (click on submit or enter key)
document.forms[0].addEventListener('submit', function (event) {
performStatistics();
// Prevent the form from refreshing the page
event.preventDefault();
});
});
Note: your script is included in the <head> of your document. Waiting for DOMContentLoaded will ensure the document is ready no matter where your script is called. But you could skip that part if you include your script at the very bottom, before the closing </body> tag.
Related
okay here is the question -- .. i tried it but my js isn't working and idk where i am wrong here is the question
THE PROBLEM IS AFTER THE JS EXECUTED IT DOESN'T RUN ... LIKE IDK WHERE THE PROBLEM IS ; I KNOW IT LOADS BUT IT DOES'NT WORK
<html>
<head>
<script src="q2.js" type="text/javascript"> </script>
</head>
<div > Input 1 <input type="text" id ="input1"></div>
<div> Input 2 <input type="text" id ="input2"> </div>
<div> Result <div id="result"> </div></div>
<button onclick= "compute()">Compute</button>
</body>
</html>
the js is here
function compute(){
var n = (document.getElementById("input1").value;
var m = document.getElementById("input2").value;
var i,j;
if (Number(n)){
}
else {
alert("Error! Please put a valid Number - on input 1 ");
}
if (Number(m)){
}
else {
alert("Error! Please put a valid Number - on input 2 ");
}
for(i = 0; i < n; i++){
for(j = 0; j < m; j++){
result.innerHTML += "X";
if(j == (m-1)){
result.innerHTML += "<br />";
}
}
}
}
result.innerHTML += "X";
You forgot to set the variable result:
var result = document.getElementById("result");
And there is a loneley ( in var n = (document.getElementById("input1").value; wich will through syntax error
And you might want to clear the content of your "result"-container when calling the function again: result.innerHMLT = ''
function compute() {
var n = document.getElementById("input1").value;
var m = document.getElementById("input2").value;
var result = document.getElementById("result");
result.innerHMLT = ''
var i, j;
if (Number(n)) {} else {
alert("Error! Please put a valid Number - on input 1 ");
}
if (Number(m)) {} else {
alert("Error! Please put a valid Number - on input 2 ");
}
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
result.innerHTML += "X";
if (j == (m - 1)) {
result.innerHTML += "<br />";
}
}
}
}
<div>Input 1
<input type="text" id="input1">
</div>
<div>Input 2
<input type="text" id="input2">
</div>
<div>Result
<div id="result"></div>
</div>
<button onclick="compute()">Compute</button>
I am trying to design a menu. If you check a box, then sum get added up and if you uncheck it, the sum is reduced. I face trouble in reducing the sum while unchecking the box and also the value of sum is not globally changed. Please help me out.
<head>
<script>
var sum=0;
function a(sum,num) {
sum=sum+num;
document.getElementById("demo").innerHTML=sum;
}
</script>
</head>
<body>
<input type="checkbox" name="Dal" id="dal" onclick=a(sum,10)>Dal<br>
<input type="checkbox" name="Rice" id="rice" onclick=a(sum,20)>Rice<br>
<h1> Total Price is : </h1>
<p id="demo"> 0 </p>
</body>
Change the markup, add a value and a class, and remove the inline JS
<input type="checkbox" name="Dal" id="dal" value="10" class="myClass">Dal
<input type="checkbox" name="Rice" id="rice" value="20" class="myClass">Rice
<h1> Total Price is : </h1><p id="demo">0</p>
Then do
<script type="text/javascript">
var inputs = document.getElementsByClassName('myClass'),
total = document.getElementById('demo');
for (var i=0; i < inputs.length; i++) {
inputs[i].onchange = function() {
var add = this.value * (this.checked ? 1 : -1);
total.innerHTML = parseFloat(total.innerHTML) + add
}
}
</script>
FIDDLE
You can do something like this:
function a (elem, num) {
var k = (elem.checked) ? 1 : -1;
sum = sum + k * num;
document.getElementById("demo").innerHTML = sum;
}
And in the HTML:
<input type="checkbox" name="Dal" id="dal" onclick="a(this, 10);">Dal<br>
<input type="checkbox" name="Rice" id="rice" onclick="a(this, 20);">Rice<br>
Try something like this:
var sum = 0;
function a(id, num) {
if(id.checked == true){
sum += num;
id.onclick = function() { a(id, num)};
}
else {
sum -= num;
id.onclick = function() { a(id, num)};
}
document.getElementById("demo").innerHTML=sum;
}
Fiddle: http://jsfiddle.net/95pvc/2/
My own take would involve removing the event-handling from the HTML (unobtrusive JavaScript) for easier maintenance in future, using data-* attributes to contain the price and using a class-name to identify the relevant ingredients, to give the following HTML:
<input class="ingredients" type="checkbox" name="Dal" data-price="10" id="dal" />Dal
<input class="ingredients" type="checkbox" name="Rice" data-price="20" id="rice" />Rice
<h1> Total Price is : </h1>
<p id="demo">0</p>
Which leads to the following JavaScript:
var ingredients = document.getElementsByClassName('ingredients');
function price() {
var result = document.getElementById('demo'),
curPrice = 0,
ingredients = document.getElementsByClassName('ingredients');
for (var i = 0, len = ingredients.length; i < len; i++) {
if (ingredients[i].checked) {
curPrice += parseFloat(ingredients[i].getAttribute('data-price'));
}
}
result.firstChild.nodeValue = curPrice;
}
for (var i = 0, len = ingredients.length; i < len; i++) {
ingredients[i].addEventListener('change', price);
}
JS Fiddle demo.
To avoid having to iterate through the relevant checkboxes, it might be better to wrap those input elements in a form, and then bind the event-handling to that form:
var ingredients = document.getElementsByClassName('ingredients');
function price() {
var result = document.getElementById('demo'),
curPrice = 0,
ingredients = document.getElementsByClassName('ingredients');
for (var i = 0, len = ingredients.length; i < len; i++) {
if (ingredients[i].checked) {
curPrice += parseFloat(ingredients[i].getAttribute('data-price'));
}
}
result.firstChild.nodeValue = curPrice;
}
document.getElementById('formID').addEventListener('change', price);
JS Fiddle demo.
References:
addEventListener().
element.getAttribute().
getElementsByClassName().
parseFloat().
Here's what i'm trying to achieve: I want to create a HTML page with a form, when you submit the form it goes to 1 of 4 locations. There is a default hidden main option thats auto-selected on page load and 2 sub-options that are optional.
Oh, and it calculates the amounts on selection!
Here's my code so far:
<html>
<head></head>
<body>
<form onSubmit="submitForm();" id="myForm" type="get">
<input id="myCheckbox1" name="myCheckbox1" type="checkbox" value="20" onClick="calcNow();" />Default option<br/>
<input id="myCheckbox2" name="myCheckbox2" type="checkbox" value="30" onClick="calcNow();" />Add-on option 1<br/>
<input id="myCheckbox2" name="myCheckbox2" type="checkbox" value="40" onClick="calcNow();" />Add-on option 2<br/>
<input id="myTotal" name="myTotal" type="text" value="" disabled="disabled" /><br/>
<input type="button" id="myButton" onClick="submitForm();" value="Continue" />
</form>
<script type="text/javascript">
var pages = [[["http://mysite.com/page1.html"],["http://mysite.com/page2.html"],["http://mysite.com/page3.html","http://mysite.com/page4.html"]]];
function calcNow()
{
var cb = document.getElementById("myCheckbox1");
var cb = document.getElementById("myCheckbox2");
var cost1 = cb.checked ? parseInt(cb.value) : 0;
var cost2 = cb.checked ? parseInt(cb.value) : 0;
var costTotal = cost1 + cost2;
document.getElementById("myTotal").value = costTotal;
var op1 = cb.checked ? 1 : 0;
if (op1 != undefined)
{
return pages[op1];
}
return undefined;
}
function submitForm()
{
var page = calcNow();
if (page != undefined)
{
alert(page);
// ---- To navigate ----
//location.href = page;
// ---- To alter post ----
//var form = document.getElementById("myForm");
//form.action = page;
//form.submit();
}
else
{
alert("Please answer all questions.");
}
}
function getRadioValue(name)
{
var controls = document.getElementsByName(name);
for (var i = 0; i < controls.length; i++) {
if (controls[i].checked) {
return parseInt(controls[i].value);
}
}
return 0;
}
function getRadioData(name, attribute)
{
var controls = document.getElementsByName(name);
for (var i = 0; i < controls.length; i++) {
if (controls[i].checked) {
return parseInt(controls[i].dataset[attribute]);
}
}
return undefined;
}
</script>
</body>
</html>
Try this
EDIT:
function submitForm()
{
//The code goes inside here, you have to decide where to redirect from if or the else
window.location.assign("http://www.w3schools.com/");
var page = calcNow();
if (page != undefined)
{
alert(page);
}
else
{
alert("Please answer all questions.");
}
}
I am trying to sort a table. I've seen several jQuery and JavaScript solutions which do this through various means, however, haven't seen any that use JavaScript's native sort() method. Maybe I am wrong, but it seems to me that using sort() would be faster.
Below is my attempt, however, I am definitely missing something. Is what I am trying to do feasible, or should I abandon it? Ideally, I would like to stay away from innerHTML and jQuery. Thanks
var index = 0; //Index to sort on.
var a = document.getElementById('myTable').rows;
//sort() doesn't work on collection
var b = [];
for (var i = a.length >>> 0; i--;) {
b[i] = a[i];
}
var x_td, y_td;
b.sort(function(x, y) {
//Having to use getElementsByTagName is probably wrong
x_td = x.getElementsByTagName('td')[index].data;
y_td = y.getElementsByTagName('td')[index].data;
return x_td == y_td ? 0 : (x_td < y_td ? -1 : 1);
});
A td element doesn't have a .data property.
If you wanted the text content of the element, and if there's only a single text node, then use .firstChild before .data.
Then when that is done, you need to append the elements to the DOM. Sorting a JavaScript Array of elements doesn't have any impact on the DOM.
Also, instead of getElementsByTagName("td"), you can just use .cells.
b.sort(function(rowx, rowy) {
x_td = rowx.cells[index].firstChild.data;
y_td = rowy.cells[index].firstChild.data;
return x_td == y_td ? 0 : (x_td < y_td ? -1 : 1);
});
var parent = b[0].parentNode;
b.forEach(function(row) {
parent.appendChild(row);
});
If the content that you're comparing is numeric, you should convert the strings to numbers.
If they are text strings, then you should use .localeCompare().
return x_td.localeCompare(y_td);
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>All Sorting Techniques</title>
<script type="text/javascript">
var a = [21,5,7,318,3,4,9,1,34,67,33,109,23,156,283];
function bubbleSort(a)
{
var change;
do {
change = false;
for (var i=0; i < a.length-1; i++) {
if (a[i] > a[i+1]) {
var temp = a[i];
a[i] = a[i+1];
a[i+1] = temp;
change = true;
}
}
} while (change);
document.getElementById("bublsrt").innerHTML = "Bubble Sort Result is: "+a;
}
var b = [1,3,4,5,7,9,21,23,33,34,67,109,156,283,318];
function binarySearch(b, elem){
var left = 0;
var right = b.length - 1;
while (left <= right){
var mid = parseInt((left + right)/2);
if (b[mid] == elem)
return mid;
else if (b[mid] < elem)
left = mid + 1;
else
right = mid - 1;
}
return b.length;
}
function searchbinary(){
var x = document.getElementById("binarysearchtb").value;
var element= binarySearch(b,x);
if(element==b.length)
{
alert("no. not found");
}
else
{
alert("Element is at the index number: "+ element);
}
}
function quicksort(a)
{
if (a.length == 0)
return [];
var left = new Array();
var right = new Array();
var pivot = a[0];
for (var i = 1; i < a.length; i++) {
if (a[i] < pivot) {
left.push(a[i]);
} else {
right.push(a[i]);
}
}
return quicksort(left).concat(pivot, quicksort(right));
}
function quicksortresult()
{
quicksort(a);
document.getElementById("qcksrt").innerHTML = "Quick Sort Result is: "+quicksort(a);
}
function numeric(evt){
var theEvent = evt || window.event;
var key = theEvent.keyCode || theEvent.which;
key = String.fromCharCode(key);
var regex = /[0-9]|\./;
if (!regex.test(key)) {
theEvent.returnValue = false;
if (theEvent.preventDefault)
theEvent.preventDefault();
}
}
function insertionsorting(a)
{
var len = a.length;
var temp;
var i;
var j;
for (i=0; i < len; i++) {
temp = a[i];
for (j=i-1; j > -1 && a[j] > temp; j--) {
a[j+1] = a[j];
}
a[j+1] = temp;
}
document.getElementById("insrtsrt").innerHTML = "Insertion Sort Result is: "+a;
}
function hiddendiv()
{
document.getElementById("binarytbdiv").style.display = "none";
document.getElementById("Insertnotbdiv").style.display = "none";
}
function binarydivshow()
{
document.getElementById("binarytbdiv").style.display = "block";
}
function insertnodivshow()
{
document.getElementById("Insertnotbdiv").style.display = "block";
}
function insertno(a)
{
var extrano = document.getElementById("Insertnotb").value;
var b= a.push(extrano);
var change;
do {
change = false;
for (var i=0; i < a.length-1; i++) {
if (a[i] > a[i+1]) {
var temp = a[i];
a[i] = a[i+1];
a[i+1] = temp;
change = true;
}
}
} while (change);
document.getElementById("insrtnosearch").innerHTML = "Sorted List is: "+a;
alert("Index of "+extrano +" is " +a.indexOf(extrano));
}
</script>
</head>
<body onload="hiddendiv()">
<h1 align="center">All Type Of Sorting</h1>
<p align="center">Your Array is : 21,5,7,318,3,4,9,1,34,67,33,109,23,156,283</p>
<div id="main_div" align="center">
<div id="bubblesort">
<input type="button" id="bubblesortbutton" onclick="bubbleSort(a)" value="Bubble Sort">
<p id="bublsrt"></p>
</div><br>
<div id="quicksort">
<input type="button" id="quicksortbutton" onclick="quicksortresult()" value="Quick Sort">
<p id="qcksrt"></p>
</div><br>
<div id="insertionsort">
<input type="button" id="insertionsortbutton" onclick="insertionsorting(a)" value="Insertion Sort">
<p id="insrtsrt"></p>
</div><br>
<div id="binarysearch">
<input type="button" id="binarysearchbutton" onclick="binarydivshow();" value="Binary Search">
<div id="binarytbdiv">
<input type="text" id="binarysearchtb" placeholder="Enter a Number" onkeypress="numeric(event)"><br>
<input type="button" id="binarysearchtbbutton" value="Submit" onclick="searchbinary()">
<p id="binarysrch">Sorted List is : 1,3,4,5,7,9,21,23,33,34,67,109,156,283,318</p>
</div>
</div><br>
<div id="Insertno">
<input type="button" id="insertno" onclick="insertnodivshow()" value="Insert A Number">
<div id="Insertnotbdiv">
<input type="text" id="Insertnotb" placeholder="Enter a Number" onkeypress="numeric(event);"><br>
<input type="button" id="Insertnotbbutton" value="Submit" onclick="insertno(a)">
<p id="insrtnosearch"></p>
</div>
</div>
</div>
</body>
</html>
I am trying to write a simple random number generator, where you input 3 integers into forms. The program then returns a certain amount of random numbers between the other two values. When I open the page the forms are displayed but when I click the button to generate the random numbers nothing happens. Why is this happening?
<html>
<head>
<script LANGUAGE="JavaScript">
function randomFromTo(from, to)
{
return Math.floor(Math.random() * ((to - from) + 1) + from);
}
function include(arr, obj)
{
for(var j = 0; j < arr.length; j++)
{
if (arr[j] == obj) return true;
}
}
function RandomGen(form)
{
var enteries = new Array();
var number = form.from.value;
var top = form.top.value;
var size = form.inputBox.value;
var count;
for (count = 0; count < size; count++)
{
var num = randomFromTo(number, top);
if (include(enteries, num) == true)
{
count--;
}
else
{
enteries[count] = num;
}
}
var i;
for(i = 0; i <= enteries.length; i++)
{
document.write(enteries[i]);
document.write("<br>");
}
}
</script>
</head>
<body>
<center><h1>Random Number Generator</h1></center>
<form name="myform" action="" method="GET">Enter the Range of Values
<input type="text" name = "from" value="">to
<input type="text" name = "top" value="">
<p>Enter The Amount of Random Numbers Needed
<input type="text" name = "inputBox" value=""><p>
<input type="button" name="button" value="Generate" onClick=RandomGen(this.form)">
</form>
</body>
You have a syntax error here
<input type="button" name="button" value="Generate" onClick=RandomGen(this.form)">
should be
<input type="button" name="button" value="Generate" onClick="RandomGen(this.form)">
Also this part should be updated, not because it will cause an error but because it is 2011
<script LANGUAGE="JavaScript">
should be
<script type="text/javascript">
Update
Or:
<script>
no need for the type attribute because it is 2018!
You missed a quote:
<input type="button" name="button" value="Generate" onClick="RandomGen(this.form)">
onclick="RandomGen(this.form)"
That part of your code was malformed. onclick is always all lower case and you were missing a "
Your missing a "
<input type="button" name="button" value="Generate" onClick="RandomGen(this.form)">