Why i can not control setinterval and clearinterval javascript?

Question

When test code it's will setinterval by not to click and when i click <div onclick="clear()">CLEAR</div> it's not clearinterval too.

How can i do for setinterval when click <div onclick="test_fn()">TEST</div> and clearinterval when click <div onclick="clear()">CLEAR</div>

<div onclick="test_fn()">TEST</div>

<script>
var xxx = null;
xxx = window.setInterval(function test_fn(){
 test_xxx();
}, 5000);



function test_xxx(){
 alert("123456789");
}
</script>

<br>
<div onclick="clear()">CLEAR</div>

<script>function clear(){
 window.clearInterval(xxx);
}
</script>

look at the error in the console ... note `test_fn` is not a global function, therefore not visible to `onclick=` — Jaromanda X, Aug 25 '18 at 07:24
try a different name for function `clear` - seems the browser doesn't like that (any other names seems to work) — Jaromanda X, Aug 25 '18 at 07:27
that's why clicking test does nothing - but - the interval is started immediately anyway — Jaromanda X, Aug 25 '18 at 07:27
i change function name to `clear_xx` it's work good for `clearinterval` but still error when `setinterval` — srimomsribo rawew, Aug 25 '18 at 07:29
because you're trying to call a function that **does not exist** — Jaromanda X, Aug 25 '18 at 07:29

Fullstack Guy · Accepted Answer · 2018-08-25T08:05:42.257

Put the logic for setInterval() in the onclick handler rather than outside of it.
Also change the clear() to any other name. As you are invoking document.clear() instead of your function. Is "clear" a reserved word in Javascript?
You can use fat arrow syntax => of ES6 to pass the callback function to setInterval().

<div onclick="test_fn()">TEST</div>
<br>
<div onclick="clear_fn()">CLEAR</div>

<script>
var xxx = null;
function test_fn(){
    alert('clicked');
    xxx = window.setInterval(() => {
     test_xxx();
   }, 5000);
}
function clear_fn(){
   alert('cleared')
   window.clearInterval(xxx);
}
function test_xxx(){
 alert("123456789");
}
</script>

Why i can not control setinterval and clearinterval javascript?

1 Answers1