Edit value of variable in a if-statment argument depending of the if-statments outcome

What I'm trying to do is to contact WooCommerce every fifth seconds to check if a product have been edited. I can do that by asking for res[0].date_modified. Then I compare the time it was created (res[0].date_created) and last modified.

If the values are the same the product have never been modified. However if the product get modified I no longer want to compare the time the product was created and last modifed.

I now want to compare the time with the last time it got modified with "res[0].date_modified" so I can see if it gets modified another time.

This is what I have come up with:

function lookForEdit(){

WooCommerce.get('products/',  function(err, WooData, res) {
    res=JSON.parse(res)

    var comp = res[0].date_created;

    if(comp == res[0].date_modified){
        console.log("the product haven't been modified")
    }
    else{
        console.log("The product have been edited")
        comp = res[0].date_modified;
    }
})
}

setInterval(lookForEdit, 5000);

I understand why it doesn't work, but I don't know how to fix it.

How can I fix it?

Thanks

Also I asked this question last week and thought I got an answer that would work. The answer I got:

var comp;


function lookForEdit(){

WooCommerce.get('products/',  function(err, WooData, res) {
    res=JSON.parse(res)
    //console.log(res[0])

    if(comp == undefined){
        console.log("The product haven't been editet")
        comp = res[0].date_created;
    }
    if(comp != res[0].date_modified){
        comp = res[0].date_modified;
        console.log("The product have been edited")
        //editAPI(res[0])

    }




});
};

Then I realised that this wouldn't work when I put the function inside a for-loop to check multiple items. I can't use "comp" if checking index 0 and index 1.

Thank you again!

via WilliamG