Okay, I'm ashamed to be asking, but it just isn't clicking. My brother-in-law has an assignment to have a text box and then a command button. When the button is pressed, it will loop 10 times printing whatever was in the text box. Should be simple - I know!
I know the error is on this line:
<input type="button" value="Press Here" onClick="sayit(document.getElementById('myTextField').value) ">
Here's what we have:
<html>
<head>
<title> Homework #11 part 2 </title>
<script type="text/javascript">
function sayIt(var message){
count = 1;
num = 10;
while (count <= num) {
document.write(message);
document.write("<br/>");
count = count + 1;
}
}
</script>
</head>
<body>
<p>
Type in a phrase.
<input type='text' id='myText' />
<br />
<input type="button" value="Press Here" onClick="sayit(document.getElementById('myTextField').value) ">
</p>
</body>
The code has three thins wrong.
1) function sayIt(var message) should be function sayIt(message)
2)onClick="sayit(....)" should be onClick="sayIt(....)"
sayIt is function name
3)document.getElementById('myTextField').value should be document.getElementById('myText')
myText is input element's id attribute
You've got three things wrong.
http://jsfiddle.net/userdude/jcfD8/
Hints - you don't need var in your function declaration, your id is not right, and you "misspelled" sayIt
( ^ If you care to see the answers, they are above ^ )
Invest in Firebug. It gave me all the answers I needed. ;)
Related
I want to write my first code. I made this, but it still needs a change.
There is shown a value and this value can be changed with 2 buttons. When the buttons Increment is pushed, the value has to go with one higher. If the button Double is pressed, then the value has to be double (e.g. going from 3 to 6). Now it is coded like a decrement, but this needs to be changed.
var x = 0
var element = document.getElementById("value");
element.innerHTML = x;
function button1() {
element.innerHTML = ++x;
}
function button2() {
element.innerHTML = --x;
}
<html>
<body>
<title> First code </title>
<body>
<div id="value"></div>
<input type=button value="Increment" onclick="button1()" />
<input type=button value="Double" onclick="button2()" />
</body>
</html>
You need to multiply by 2 rather than subtract 1.
There's no need for the x variable, you can operate directly on the innerHTML. JavaScript's type juggling will automatically convert it to a number when you use these arithmetic operators on it.
var element = document.getElementById("value");
element.innerHTML = '0';
function button1() {
element.innerHTML++;
}
function button2() {
element.innerHTML *= 2;
}
<html>
<body>
<title> First code </title>
<body>
<div id="value"></div>
<input type=button value="Increment" onclick="button1()" />
<input type=button value="Double" onclick="button2()" />
</body>
</html>
This question already has an answer here:
The values for document.getElementById().value are null
(1 answer)
Closed 10 months ago.
I am trying JavaScript and HTML with a little CSS (that is not required), and I can't seem to define this variable.
I have the element id with this HTML code:
<p class="margin"><b>Got </b>
</p><input type="text" class="margin" id="iGotThis">
<p class="margin"><b> out of </b></p>
<input type="text" class="margin" id="outOfThis">
and get it into a variable with js and this code:
var made = document.getElementById("iGotThis").value;
var total = document.getElementById("outOfThis").value;
var perMade = made / total;
and I am trying to alert the result with an alert function:
document.getElementById("submit").click();
}
});
function perFunction() {
alert(total);
};
Here is the full code:
<!DOCTYPE html>
<html>
<head>
<style>
.margin {
margin-left: 80px;
}
</style>
</head>
<body>
<br>
<br>
<p class="margin"><b>Got </b></p><input type="number" class="margin" id="iGotThis"><p class="margin"><b> out of </b></p><input type="number" class="margin" id="outOfThis">
<br>
<br>
<input type="submit" id="submit" class="margin" onclick="perFunction()">
<script>
var iGotThis = document.getElementById("iGotThis").value;
let outOfThis = document.getElementById("outOfThis").value;
var perMade = iGotThis / outOfThis;
// This entire portion has no use for the variables
var input = document.getElementById("outOfThis");
input.addEventListener("keyup", function(event) {
if (event.keyCode === 13) {
event.preventDefault();
document.getElementById("submit").click();
}
});
// This is where the useless section ends
function perFunction() {
alert(iGotThis.value);
};
</script>
</body>
</html>
I have tried just alerting the variable made or total but just comes up blank. I can't think of a solution so I am hoping someone can help. I am still pretty new to this stuff and can't so everything.
there is no ID as "total" in the HTML code. Please check that
Input type=textbox is wrong. You can use type=text. Maybe the browser doesn't understand textbox's value, because textbox isn't an official HTML type value. You see an textbox, because the browser doesn't know what IT should use.
I'm 3 days into learning Javascript and im really excited to understand more of this language, before i started i've done a basic HTML & CSS education. I'm currently on a 2 year program in a University in Sweden.
I'm trying to create a very basic calculator, that for now only adds 2 numbers together. I have 1 box, and another box. I want to make that each number written in each of these boxes is displayed as the total of box1, box2 in the third and final box.
At this moment i get "NaN" in the 3rd box when trying to add 2+3.
As i said, I'm really new and i appreciate all help i can get, and note that im not here for anyone to do my assignments which we have plenty of, i am really interessted in learning and understanding the language because i would like to work with this later in life when im done with my education.
Cheers!
<h1>Addera två tal med varandra</h1>
<form>
<input type="text" value="0" id="tal1" /> <br>
<input type="text" value="0" id="tal2" /> <br>
<input type="button" value="Beräkna" onClick="kalkylera();" />
<p>Den totala summan är</p>
<input type="text" value="0" id="svar" />
</form>
<script>
function kalkylera() {
//Get the two numbers entered in the box
var ForstaTalet = document.getElementById("tal1").value;
var AndraTalet = document.getElementById("tal2").value;
//Count the two entered numbers together
var svar = tal1 + tal2;
//Show result
document.getElementById("svar").value = svar;
}
</script>
PS, I'm not sure why "//# sourceURL=pen.js" is written i the bottom of the calculator when adding this to the codepen, that is not how it looks when viewing it in chrome.
Thanks in advance.
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<title>Calculator</title>
</head>
<body>
<form>
<input type="text" placeholder='num1' id="tal1"/> <br>
<input type="text" placeholder='num2' id="tal2"/> <br>
<input type="button" value="Add" onClick="sum()"/>
<input type="text" placeholder='sum' id="svar"/>
</form>
<script>
function sum()
{
var ForstaTalet = parseFloat(document.getElementById("tal1").value);
var AndraTalet = parseFloat(document.getElementById("tal2").value);
var svar = ForstaTalet + AndraTalet;
document.getElementById("svar").value = svar;
}
</script>
</body>
</html>
This works fine.
You need to cast your values as float with parseFloat and use the right variables as in the following example:
//Get the two numbers entered in the box
var ForstaTalet = parseFloat(document.getElementById("tal1").value);
var AndraTalet = parseFloat(document.getElementById("tal2").value);
//Count the two entered numbers together
var svar = ForstaTalet + AndraTalet;
//Show result
document.getElementById("svar").value = svar;
I cant for the life of me figure out why the following is not working. I took if from the W3school example here.
Basically I want to take the value from the input text when it changes and modify another div to include the value. I only want the div to show the new value, but I do want it to change it each time so I figured the onchange was the way to go.
<!DOCTYPE html>
<html>
<head>
<script>
function myFunction()
{
var div = document.getElementById('divID');
div.innerHTML = div.innerHTML + x.value;
}
</script>
</head>
<body>
Enter your name: <input type="text" id="fname" onchange="myFunction()">
<p>When you leave the input field, a function is triggered which transforms the input text to upper case.</p>
<div id="divID"></div>
</body>
</html>
Thanks in advance for all the help on this one.
You have 2 problems, first is that x is undefined.
second you should use another trigger for this for this to happen each time.
try this out:
function myFunction()
{
var input = document.getElementById('fname')
var div = document.getElementById('divID');
div.innerHTML = div.innerHTML + input.value;
}
and change your html to:
<input type="text" id="fname" onkeypress="myFunction()">
x is undefined in your function, it should be document.getElementById('fname').
And if you want to change the div each time you press the key, use onkeyup or onkeypress instead of onchange.
You may change x.value to document.getElementById("fname").value, if I understand your question correctly.
<head>
<script type="text/javascript">
function input(){
var input_taker = document.getElementById('email').value;
document.getElementById('display').innerHTML = input_taker;
}
</script>
</head>
<form method="post" action="#">
<input type="text" name="email" placeholder="email#example.com" id="email" onchange="input()">
<input type="submit" name="save" value="save">
</form>
<div id="display"></div>
Ok, so check this out - http://jsfiddle.net/2ufnK/2/
The issue is that you need to define x here,
var x = document.getElementById("fname");
x now references to the html object.
Then you can just call the, ".value", method to get its text. Then everything else works the way you've written it.
Beginer to javasctipt. I am trying to write a simple calculation that will display some text if the time since oil change is past 6 months, the amount of oil left in the car is less then it started and finally display if everything is ok.
Thanks for the help
JavaScript
function oil(){
var start = document.oil.start.value;
var lastOilChange = document.oil.time.value;
var totalOil = document.oil.amount.value;
var aa = "you need to change the oil";
if( lastOilChange > 6 || start < totalOil){
document.oil.result.write(aa);
}else{
document.oil.result.write("Everything Is all good");
}
}
HTML
<form name="oil">
Starting amount of oil
<input type="text" name="start">
Time since oil change
<input type="text" name="time">
Total amount of oil in car now(quarts)
<input type="text" name="amount">
<input type="submit" onclick = oil()>
<input name=result readonly>
</form>
There are a couple of problems with your code
Missing Form close tag
Your controls don't have IDs
missing quotes on the result input
Don't need to use a submit input when you're not submitting to a form. Try button
Not sure what document.oil.result.write(aa); will do. I think the correct process is to get the input using document.getElementById and then set the value of the control
I will try to answer your question with the least number of line changes. This is not the optimal answer. Comments have been added to help you understand required changes. Your HTML and JavaScript are invalid, so it was a surprise to me how they both ran on Chrome.
<!doctype>
<html>
<head>
<title>Personal</title>
<meta charset="utf-8">
<script type="text/javascript">
function _oil(){ // oil() conflicts with your form's name
var start = document.oil.start.value;
var lastOilChange = document.oil.time.value;
var totalOil = document.oil.amount.value;
var aa = "you need to change the oil";
if( lastOilChange > 6 || start < totalOil){
document.write(aa); // you can't .write() to an element
}else{
document.write("Everything Is all good");
}
window.event.preventDefault(); // so your window does not load the same page when you submit
return false;
}
</script>
<style>
form input {
display: block;
}
</style>
</head>
<body>
<form name="oil">
Starting amount of oil
<input type="text" name="start">
Time since oil change
<input type="text" name="time">
Total amount of oil in car now(quarts)
<input type="text" name="amount">
<input type="submit" onclick ="_oil()"> <!-- you must enclose the onclick attribute, even if both work -->
<input name=result readonly>
</body>
</html>
May be like this:
<!doctype>
<html>
<head>
<title>Personal</title>
<meta charset="utf-8">
<script type="text/javascript">
function oil(){
var start = document.getElementsByName("start")[0].value;
var lastOilChange = document.getElementsByName("time")[0].value;
var totalOil = document.getElementsByName("amount")[0].value;
var aa = "you need to change the oil";
if( lastOilChange > 6 || start < totalOil){
document.getElementsByName("result")[0].value = aa;
}else{
document.getElementsByName("result")[0].value = "Everything Is all good";
}
}
</script>
<style>
form input {
display: block;
}
</style>
</head>
<body>
<form name="thisform">
Starting amount of oil
<input type="text" name="start">
Time since oil change
<input type="text" name="time">
Total amount of oil in car now(quarts)
<input type="text" name="amount">
<input type="button" value="go" onclick = oil()>
<input name=result readonly>
</form>
</body>
</html>
！！！ The form name can not use oil
What you want is to set the value of the form field rather than trying to use write:
if( lastOilChange > 6 || start < totalOil){
document.oil.result.value = aa;
} else {
document.oil.result.value = "Everything Is all good";
}
As pointed out in other answers, though, you also need to prevent the form from trying to submit information to the server and reload the page. There are several ways of doing this (see e.g. JavaScript code to stop form submission). One is to replace the submit button with an ordinary button (<input type="button" value="Calculate" />).
Another is to attach your function to the form as an event handler, and return false at the end of it.
document.oil.onsubmit = function () {
...
return false;
}
(JSFiddle)