useEffect(() => { // define increment counter part const tabsOpen = localStorage.getItem('tabsOpen') console.log('tabsOpen', tabsOpen) if (tabsOpen == null) { localStorage.setItem('tabsOpen', 1) } else { localStorage.setItem('tabsOpen', parseInt(tabsOpen) + parseInt(1)) } // define decrement counter part window.onunload = function (e) { const newTabCount = localStorage.getItem('tabsOpen') if (newTabCount !== null) { localStorage.setItem('tabsOpen', newTabCount - 1) } } }, [])