**expected expression, got end of script Javascript function - javascript

I have this as my function, it's currently just a test.
<button onclick=function test()>Test The Function!</button>
<script>
function test(){
return('Try Again!')
}
</script>
According to the console whenever I call on the function, "expected expression, got end of script"
Are there any errors or am I doing this wrong? The function is in the head.
Edit: In response to the comments, this is my code after attempting to do what the comments said. Note: This does not work for me. I am using Firefox, and it is on the f12 editor on the about:blank page.
<html><head></head><body>
<script>
function test() {
alert("You clicked the button");
}
</script>
<button onclick="test()">Using Javascript</button>
</body></html>
Yes, I know this works in the snippet or fiddle, but it doesn't work in the html code in an about:blank page. Can anyone figure out the problem? I click the button and NOTHING happens.

You need to update your code to:
<button onclick="test()">Test The Function!</button>
You will also have to move the function definition before the call in the html, or else test will be undefined.

Few issues I see:
Wrap the function call in "
Create script above the template
Calling the function without the word function
Where do you expect to return in the function? If you want to see something in the console use console.log or if you want an alert use alert().
Not all of those are wrong but its best to struct them like that.
fiddle: https://jsfiddle.net/8x0avrv5/
Complete code:
<script>
function test(){
alert('Try Again!');
}
</script>
<button onclick="test()">Test The Function!</button>

To answer your question this is the correct syntax:
<button onclick="return click1()">
Using javascript
</button>
javascript
function click1() {
alert("You clicked the button");
return true;
}
As another option you can use Jquery instead
<button id="click">
Using jquery
</button>
Jquery
$("#click").click(function() {
alert("You clicked the button");
});
See examples here: https://jsfiddle.net/hzkwxo3q/2/

Related

Not getting alert when first selecting an option on dropdown menu [duplicate]

This question already has answers here:
Why isn't my JavaScript working in JSFiddle?
(7 answers)
Closed 3 months ago.
There is some code I wanted to put into JSFiddle. It didn’t work. Narrowing it down I can’t even get this simplest of code to work:
JSFiddle
function displaymessage() {
alert("Hello World!");
}
<form>
<input type="button" value="Click me!" onclick="displaymessage()" />
</form>
<p>By pressing the button above, a function will be called. The function will alert a message.</p>
The alert box doesn’t show up in the JSFiddle.
Select No wrap - bottom of <head> in the “Load type” dropdown in the JavaScript settings.
You need to take your function out of the onLoad/onReady otherwise it is placed inside of another scope and your button cannot access the function. In your case you need to use
No wrap (head)
The code generated looks like this:
Ext.onReady(function() {
function displaymessage()
{
alert("Hello World!");
}
});
Change the code to run "no wrap (head)" instead of "onDomReady". Your function isn't visible to your markup as is.
Maybe some of you need to move your function outside of document.ready if you use html onclick="func()"
$(document).ready(function() {
...
}
function func(){
...
}
If you still have problems, check whether you have
AdBlockers installed as a browser extension? (i.e. AdBlocker Plus)
Turn off AdBlockers in JSFiddle and run again.
I hope this helps some one.
Thanks.
Sorry but... is much simpler than what you propose...
If you want to call a js function with "onclick" attribute, put your javascrit code directly in head, you dont need domready or similars.
Second, you need to include "javascript:" before the function name.
See: http://jsfiddle.net/XNJxT/1838/
<input type="button" value="Click me!" onclick="javascript:displaymessage()" />
My problem to this was when I made my script tag I typed it out :
script type="javascript/text"
instead of :
script type="text/javascript"
and now it works.
http://jsfiddle.net/praveen_prasad/XNJxT/14/
Js fiddle so something like this to whatever you write
window.addEvent('load',function(){
//Your code
});

JavaScript function not found on jsfiddle

Very simple minimal jsfiddle example:
https://jsfiddle.net/a9f2j4xo/
Clicking the button should invoke the Bla() function.
When I click the button the console says
ReferenceError: Bla is not defined.
Who or what is malfunctioning here, jsfiddle or my brain?
You need to wrap the function script inside <head> . Otherwise your script is not invoked.
Change the settings as
LOAD TYPE - Wrap in <Head>
WORKING DEMO
This seems to be something weird. Because on putting it inside script tag it is working. See js fiddle here https://jsfiddle.net/a9f2j4xo/
<button onclick='Bla()'>
Test
</button>
<script>
function Bla()
{
alert('yes');
}
</script>

JavaScript button onclick not working

<button onclick="hello()">Hello</button>
<script>
function hello() {
alert('Hello');
}
</script>
This is my code. But it's not working. When I click on the button nothing happens.
Note to other developers coming across this, you can run into this if you use a reserved method names e.g. clear.
<!DOCTYPE html>
<html>
<body>
<button onclick="clear()">Clear</button>
<button onclick="clear2()">Clear2</button>
<script>
function clear() {
alert('clear');
}
function clear2() {
alert('clear2');
}
</script>
</body>
</html>
How about this?
<button id="hellobutton">Hello</button>
<script>
function hello() {
alert('Hello');
}
document.getElementById("hellobutton").addEventListener("click", hello);
</script>
P.S. You should place hello() above of the button.
Ran into this problem myself so I can confirm something's not right. The difference is that I am generating the DOm Element at runtime. Replacing onclick with onmousedown seemed to do the trick if you can't find a place to addEventListener in your code.
I had a similar issue. I had child.js and a common.js files. In my case, My HTML file was using both the JS files and both of them had a function with the same name,
child.js
function hello(){}
and also
common.js
function hello(){}
After I remove one of these my code works fine and onclick started working. hope this helps!
using onclick vs EventListeners.
The question is a matter of browser compatibility and necessity. Do you need to attach more than one event to an element? Will you in the future? Odds are, you will. attachEvent and addEventListener are necessary. If not, an inline event may seem like they'd do the trick, but you're much better served preparing for a future that, though it may seem unlikely, is predictable at least. There is a chance you'll have to move to JS-based event listeners, so you may as well just start there. Don't use inline events.
jQuery and other javascript frameworks encapsulate the different browser implementations of DOM level 2 events in generic models so you can write cross-browser compliant code without having to worry about IE's history as a rebel. Same code with jQuery, all cross-browser and ready to rock:
$(element).on('click', function () { /* do stuff */ });
Don't run out and get a framework just for this one thing, though. You can easily roll your own little utility to take care of the older browsers:
function addEvent(element, evnt, funct){
if (element.attachEvent)
return element.attachEvent('on'+evnt, funct);
else
return element.addEventListener(evnt, funct, false);
}
// example
~```
addEvent(
document.getElementById('myElement'),
'click',
function () { alert('hi!'); }
);
Try it: http://jsfiddle.net/bmArj/
Taking all of that into consideration, unless the script you're looking at took the browser differences into account some other way (in code not shown in your question), the part using addEventListener would not work in IE versions less than 9.
There is no problem with your code.. run this snippet
function hello() {
alert('Hello');
}
<button onclick="hello();">Hello</button>
and if you want to alert this on window load. change your code like this way
(function(){
alert('hello')
})();
Add:
type="button"
to the button element. The default type is "submit" which is submitting the form before the script is run.
In my case there are was two same elements with position: absolute. I set onclick on the first one so it haven't been called because second element was covering it
I had the same issue, for me, it did not work because of my main.js having type="module", if you don't need type="module" this will work.
<body>
<button onclick="onBtSave()">Save filter model script type module</button>
<button onclick="onBtRestore()">Restore filter model no script type</button>
<script type="module">
// broken
function onBtSave() {
console.log("saving current filter model");
}
</script>
<script >
// working
function onBtRestore() {
console.log("restoring current filter model");
}
</script>
This happened to me when I opened another folder in visual studio code. I just opened new window of visual studio code and only opened one folder this time and it now works
I had the same problem and that's because of reserved method names. We just change the function name.
function click() {
alert('hi')
}
function click1234() {
alert('hi')
}
<body>
<button onclick="click()">login</button>
<button onclick="click1234()">login1234</button>
</body>
For other devs with more advanced code, sometimes an absolute position element is blocking the button. Make sure no element is blocking the button(s) from being clicked.
Write a semicolon after hello function like this
<button onclick="hello();">Hello</button>

Why does this simple JSFiddle not work? [duplicate]

This question already has answers here:
Why isn't my JavaScript working in JSFiddle?
(7 answers)
Closed 3 months ago.
There is some code I wanted to put into JSFiddle. It didn’t work. Narrowing it down I can’t even get this simplest of code to work:
JSFiddle
function displaymessage() {
alert("Hello World!");
}
<form>
<input type="button" value="Click me!" onclick="displaymessage()" />
</form>
<p>By pressing the button above, a function will be called. The function will alert a message.</p>
The alert box doesn’t show up in the JSFiddle.
Select No wrap - bottom of <head> in the “Load type” dropdown in the JavaScript settings.
You need to take your function out of the onLoad/onReady otherwise it is placed inside of another scope and your button cannot access the function. In your case you need to use
No wrap (head)
The code generated looks like this:
Ext.onReady(function() {
function displaymessage()
{
alert("Hello World!");
}
});
Change the code to run "no wrap (head)" instead of "onDomReady". Your function isn't visible to your markup as is.
Maybe some of you need to move your function outside of document.ready if you use html onclick="func()"
$(document).ready(function() {
...
}
function func(){
...
}
If you still have problems, check whether you have
AdBlockers installed as a browser extension? (i.e. AdBlocker Plus)
Turn off AdBlockers in JSFiddle and run again.
I hope this helps some one.
Thanks.
Sorry but... is much simpler than what you propose...
If you want to call a js function with "onclick" attribute, put your javascrit code directly in head, you dont need domready or similars.
Second, you need to include "javascript:" before the function name.
See: http://jsfiddle.net/XNJxT/1838/
<input type="button" value="Click me!" onclick="javascript:displaymessage()" />
My problem to this was when I made my script tag I typed it out :
script type="javascript/text"
instead of :
script type="text/javascript"
and now it works.
http://jsfiddle.net/praveen_prasad/XNJxT/14/
Js fiddle so something like this to whatever you write
window.addEvent('load',function(){
//Your code
});

function onclick not working .. ... not showing alert box

html code
<input type="button" value="+" onclick="alert()" />
In chrome after inspecting it showing this error Uncaught RangeError: Maximum call stack size exceeded.
javascript
<script type="text/javascript">
function alert() {
alert("Hello! I am an alert box!!");
}
</script>
help me by telling how to solve this
You override the existing function definition with new definition, which in addition is calling itself, causing too much recursion.
As other users mentioned you just need to create your function with a different name than alert() which is an already defined function in javascript, you shouldn't be using that.
I would rather use the standard addEventListener, will make your code cleaner as well as your html
You can do something like this, also you can try it right from this page:
function myDefinedAlert() {
alert("Hello! I am an alert box!!");
}
var el = document.getElementById("yourButton");
el.addEventListener("click", myDefinedAlert, false);
<input id="yourButton" type="button" value="+" />
Press the button, try it, and copy it to your code, let me know if it works :)
that's because you call alert() in alert(), so it turns out in recursion.
The alert() is a built-in function, which is not meant to be redefined. Although you redefine, you are calling the same function inside the new function, which is wrong. So, in simple terms, give a different name like myAlert() or something:
function myAlert() {
alert("Hello! I am an alert box!!");
}
So recursively the alert() function gets called and it overflows the stack.
Solution Snippet
function myAlert() {
alert("Hello! I am an alert box!!");
}
<input type="button" value="+" onclick="myAlert()" />
You can not have a recursive function such as what you have done here in Javascript as it would continue to loop out of control and consume more memory in the browser. When you call a function from within a function you need to make sure that you are not calling the same function.

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