ClearInterval not clearing SetInterval

Question

When we call clearInterval with the value returned by SetInterval does it make that value null or undefined. I am calling clearInterval to clear setInterval but apparently value of setInterval remains same and does not change even after calling clearInterval . Is t suppposed to be null or undefined ? Here is my code snippet ``` var setIntervalId; // declared in global scope //lined of code function autorefresh() { if (statesCount > 0) { setIntervalId = setInterval(function() { //lines of code // calling some handler }, 30000); } if (statesCount === 0) { clearInterval(setIntervalId); } } ``` As you can see I am calling my setInterval function every 30 seconds , when called for the first time assigns some value to setIntervalId , but even after calling clearInterval the value persists. Should it become null or undefined after calling clearInterval?If it should be null or undefined what should I do here.I have defined setIntervalId in global scope.

Accepted Answer

The function `clearInterval` will not clear the value that is passed into it. If you want to clear it you must do that yourself

```
clearInterval(setIntervalId);
setIntervalId = undefined;
```

Note that it doesn't appear like you are properly guarding the initial call to `setInterval`. This could result in the call being made multiple times and hence you having multiple interval setups. I think you should augment your initial `if` block to the following

```
if (statesCount > 0 && typeof(setIntervalId) === 'undefined') { 
  ...
}
```

ClearInterval not clearing SetInterval

Solution

Problem