My results of calculation appear on a different page - javascript

I need to create code which automatticaly calculates the circumference when the length and width are entered in two different boxes.
I managed to do so, but I want the answer to appear underneath the "calculate" button, but the answer will make the button and boxes disappear. Could someone tell me what I need to change?
Here is my code:
<!DOCTYPE html>
<html>
<body>
<form>
Width:<br>
<input id="Width" type="text" name="Width">
<br>Length<br>
<input id="Length" type="text" name="Length">
<br><br>
<input type="button" value="Calculate circumference" onclick="doMath()">
</form>
<script>
function doMath() {
var Width1 = document.getElementById('Width').value;
var Length1 = document.getElementById('Length').value;
var Circ = parseInt(Width1) + parseInt(Width1) + parseInt(Length1) + parseInt(Length1);
document.write(Circ);
}
</script>
</body>
</html>

Do not use document.write function. The write() method is mostly used for testing: If it is used after an HTML document is fully loaded, it will delete all existing HTML. Create a paragraph tag and give an id and place your result in that paragraph.
<!DOCTYPE html>
<html>
<body>
<form>
Width:<br>
<input id="Width" type="text" name="Width">
<br>Length<br>
<input id="Length" type="text" name="Length">
<br><br>
<input type="button" value="Calculate circumference" onclick="doMath()">
<p id="result">
</p>
</form>
<script>
function doMath() {
var Width1 = document.getElementById('Width').value;
var Length1 = document.getElementById('Length').value;
var Circ = parseInt(Width1) + parseInt(Width1) + parseInt(Length1) + parseInt(Length1);
//document.write(Circ);
document.getElementById("result").textContent = Circ;
}
</script>
</body>
</html>

Try adding a black paragraph to the html and then use document.getElementById("").innerHTML to change the text inside of it.

Related

Pure Js (3 input calculated in real time)?

Build a basic calculator.
<html>
<body>
<input class="numb1" type=number name="secondBox" value="">
<input class="numb2" type=number name="secondBox" value="">
<input class="numb3" type=number name="thirdBox" value="" readonly>
</body>
</html>
<html><input type='number' id='one' placeholder='00' onblur='calculate()'>
/
<input type='number' id='two' placeholder='00' oninput='calculate()'>
<input type='number' id='result' placeholder='Result' disabled>
<script>
function calculate(){
var one = document.querySelector('#one').value;
var two = document.querySelector('#two').value;
var result = document.querySelector('#result');
result.value = Math.floor(one/two);
}
</script>
</html>
Here is a working example:
var evN1 = document.getElementById("no1Box");
evN1.addEventListener("input", calculate, false);
var evN2 = document.getElementById("no2Box");
evN2.addEventListener("input", calculate, false);
function calculate() {
var n1 = document.getElementById("no1Box").value;
var n2 = document.getElementById("no2Box").value;
var r = n1/n2;
document.getElementById("result").innerHTML = "Result: " + r;
}
body {padding:0;margin:0;font-family:Arial,Helvetica,sans-serif;}
div {margin:15px;}
label {display:block;}
input {border:solid 1px #888;font-size:20px;border-radius:5px;padding:2px;outline:none;}
.myInput {box-shadow:0 0 4px green;}
<!DOCTYPE html>
<html>
<body>
<label for="input">Input 1</label>
<input class="myInput" id="no1Box" type=number name="firstBox" value="">
<label for="input">Input 2</label>
<input class="myInput" id="no2Box" type=number name="secondBox" value="">
<p id="result"/>
</body>
</html>
Through document.getElementById("no1Box"); you take the element with the uniquie id that you set on html see more about getElementById here and by using .value you get the value that you introduced in your input.
After taking the element var evN2 = document.getElementById("no2Box"); add a listener to him evN2.addEventListener("input", calculate, false); and tell what function should execute when the input is changed. more examples for eventListener here
If you have questions, feel free to ask.

Adding Number by javascript

<html>
<head>
<title>JavaScript - using function</title>
<script>
function add(){
var value1=document.getElementById("n1").value;
var value2=document.getElementById("n2").value;
document.getElementById("result").value=parseFloat(value1)+parseFloat(value2);
}
</script>
</head>
<body>
<label>First Number:<input type="number" id="n1"/></label>
<label>Second Number:<input type="number" id="n2"/></label>
<input type="button" value="Add" onClick="add()" />
<p>
Result = <span id="result" ></span>
</p>
</body>
</html>
I am new to JavaScript and wanted to create a script that add numbers up. After pressing "Add" button, I cannot get the result to be displayed. How to get the result displayed?
Two things wrong here...
1)
<input type="button" value="Add" /> change it to
<input type="button" value="Add" onclick="add()" />
Also,
2)
document.getElementById("result").value=parseFloat(value1)+parseFloat(value2);
to
document.getElementById("result").innerHTML=parseFloat(value1)+parseFloat(value2);
PS : This is not a assignment solving website :P
First, You Should Change
document.getElementById("result").value = value1 + value2
To This:
document.getElementById("result").innerHTML = n1 + n2
Because value stands for the attribute value for < input >, not the text written
in the tag.
Second, Change The Button Code To:
<input type="button"value="Add"onclick="add()">
This "onclick" is something called event in javascript,
It means at clicking on the button "Add" it performs the funtion called "add()".
If You Are New To Javascript You Will Know Everything.
Just Be Patient.
It worked with the following changes
-> calling add function with onclick event
-> using innerhtml in place of value
<html>
<head>
<title>JavaScript - using function</title>
<script>
function add(){
var value1=document.getElementById("n1").value;
var value2=document.getElementById("n2").value;
console.log(value1,value2)
document.getElementById("result").innerHTML=parseFloat(value1)+parseFloat(value2);
}
</script>
</head>
<body>
<label>First Number:<input type="number" id="n1"/></label>
<label>Second Number:<input type="number" id="n2"/></label>
<input type="button" value="Add" onclick="add()"/>
<p>
Result = <span id="result" ></span>
</p>
</body>
</html>
Hope this helps
Its better to put the js at the end of the document - also as noted the onclick handler needs to call the function. I also tidied up the code a little.
<html>
<head>
<title>JavaScript - using function</title>
<style>label{display:block}</style>
</head>
<body>
<label>First Number:<input type="number" id="n1"/></label>
<label>Second Number:<input type="number" id="n2"/></label>
<input type="button" value="Add" onclick="add()">
<p>Result = <span id="result" ></span></p>
<script>
function add(){
var value1=parseFloat(document.getElementById("n1").value);
var value2=parseFloat(document.getElementById("n2").value);
var total= value1 + value2;
document.getElementById("result").innerText=total;
}
</script>
</body>
</html>

Output in a textbox in a webpage

I'm trying to input 2 parameters and output it an another TEXTBOX.
This is my code:
<!DOCTYPE html>
<html>
<head>
<script src="proj4js/lib/proj4js/lib/proj4js-compressed.js"></script>
</head>
<body>
<script>
function func1 (x,y){
var z=x+y
document.getElementById("Z").innerHTML = z;
}
</script>
<form >
first input:<br>
<input id="Y" type="text" y="Y" value=85>
<br>
second input:<br>
<input id="X" type="text" x="X" value=15>
<br>
The Answer:<br>
<input id="Z" type="text" z="Z" >
<br><br>
</form>
<button type="button" onclick="func1(parseInt(document.getElementById('X').value),parseInt(document.getElementById('Y').value))">Try it</button>
What is wrong here? I tried this to show the result as simple paragraph and I succeed, but I need to display it in a textbox.
Replace this:-
document.getElementById("Z").innerHTML = z;
with
document.getElementById("Z").value = z;
An <input> element uses value and not innerHTML:
document.getElementById("Z").value = z;

Create a "calculation form" in javascript

so I have a project now, as an addition to my company's website, we want to show our clients how much they can save on gas by buying one of our electric cars, I'm responsible for making it happen, I don't know how to approach this using javascript, can you guys give me a hand? our marketing guy got the idea from this website, that is basically what we want, but I was hoping i could make it a little better on some aspects:
1st-the client wouldn't have to press submit to see the results, as they fill the last field, the calculated part is populated automatically, for this i've been fiddling with the onChange event, unsuccessfully though xD
here's what I have so far, it is not working, at least on dreamweaver's live mode, haven't tested it online yet as I was hoping to develop the whole thing offline:
<script type="text/javascript">
function calc(){
var km=document.getElementById(km).value;
var euro=document.getElementById(euro).value;
var consumo=document.getElementById(consumo).value;
var cem_km=consumo*euro;
var fossil_day=(cem_km*km)/100;
return fossil_day;
}
</script>
<form name="calc" id="calc" >
<p>
Km/dia
<input type="text" name="km" id="km" value="" />
</p>
<p>
€/Litro
<input type="text" name="euro" id="euro" value="" />
</p>
<p>
Litros/100km
<input type="text" onChange="calc()" name="consumo" id="consumo" value="" />
</p>
<input type="button" onClick="calc()" name="submit" id="submit" value="Calcular" />
<script type="text/javascript">
var fossil_day = calc();
document.write('<p>'+fossil_day+'</p>');
</script>
</form>
Please note that although I have this already, I wouldnt mind not doing this at all and using another solution, even if it doesnt use forms, I'm just showing what i have already so you can tell me how I'm wrong and how I can have a better approach at it
there are many errors inside your code
document.getElementById() needs the element id in brackets ''
you can't create a element with the same name,id as a function calc else it will throw an error as it's an object and not a function.
your executing the function onload... but you want it to be executed when the button is clicked & onchange.
you don't need to add value if empty and name if you use getElementById
return false in the function on buttons inside form else it could send the form and so refresh the page.
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>calc</title>
<script>
function calc(){
var km=document.getElementById('km').value;
var euro=document.getElementById('euro').value;
var consumo=document.getElementById('consumo').value;
var cem_km=consumo*euro;
var fossil_day=(cem_km*km)/100;
document.getElementById('result').innerHTML=fossil_day;
return false
}
</script>
</head>
<body>
<form>
<p>Km/dia<input type="text" id="km"/></p>
<p>€/Litro<input type="text" id="euro" /></p>
<p>Litros/100km<input type="text" onChange="calc()" id="consumo" /></p>
<input type="button" onClick="calc()" value="Calcular" />
</form>
<div id="result"></div>
</body>
</html>
Useing jQuery (and html5 type="number" form fields):
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<form>
<p>
Km/dia
<input type="number" name="km" id="km" value="" />
</p>
<p>
€/Litro
<input type="number" name="euro" id="euro" value="" />
</p>
<p>
Litros/100km
<input type="number" name="consumo" id="consumo" value="" />
</p>
<div id="fossil-day"></div>
</form>
<script src="http://codeorigin.jquery.com/jquery-1.10.2.min.js"></script>
<script>
function calculate(){
var km = $('#km').val();
var euro = $('#euro').val();
var consumo = $('#consumo').val();
var cem_km = consumo*euro;
var fossil_day = (cem_km*km)/100;
$('#fossil-day').html(fossil_day);
}
$(function() {
/*when #consumo input loses focus, as per original question*/
$('#consumo').blur(function(){
calculate();
});
});
</script>
</body>
</html>

Javascript flashing for a second but not printing in textbox

Amount
<script type="text/javascript">
<!--
function interestVal()
{
var x = document.Amounts.valOfCar.value;
var y = document.Amounts.interestofCar.value;
var z = x+y;
document.Amounts.carInterest.value=z;
}
-->
</script>
</head>
<body background="bg.jpg">
<p>Calculate the cost of your car</p>
<form name = Amounts>
<p>Value of a car <input type="text" value="" name=valOfCar></p>
<p>Interest #15% <input type="text" value="" name=interestofCar></p>
<p>Value + Interest<input type="text" name=carInterest></p>
<p><input type=submit value=Calculate onClick=interestVal()></p>
</form>
</body>
Here you go. I was able to reproduce your problem by just copying your code and running it. This code will run. The principal change I made, which I believe was the source of the problem, was altering from an input of type submit to a button. As a submit, it was doing a postback, which caused the contents of the controls to disappear. Using a button avoids the postback.
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
<!--
function interestVal() {
var x = document.Amounts.valOfCar.value;
var y = document.Amounts.interestofCar.value;
var z = x * y;
document.Amounts.carInterest.value = z;
}
-->
</script>
</head>
<body background="bg.jpg">
<p>Calculate the cost of your car</p>
<form name = "Amounts">
<p>Value of a car <input type="text" name="valOfCar" /></p>
<p>Interest #15% <input type="text" name="interestofCar" /></p>
<p>Value + Interest<input type="text" name="carInterest" /></p>
<p><button type="button" onclick="interestVal();" >Calculate</button></p>
</form>
</body>
</html>
Another potential problem is that by summing x and y, you get their concatenated result, which is probably not what you want. I have changed that to multiplying x times y.
Finally, I have enclosed many of the attribute values in quotes and made the inputs self-closing by ending the with /> instead of >.

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