js模拟实现一个localStorage

const localStorageMock = (function() {
	let store = {}
	return {
				 
         getItem: function(key) { return store[key] || null },				 
         setItem: function(key, value) { store[key] = value.toString() },			 
         removeItem: function(key) { delete store[key] },clear: function() { store = {} },
	}
})()
Object.defineProperty(window, 'localStorage2', {
			value: localStorageMock
})
		localStorage2.setItem('test', 'test')
		console.log(localStorage2.getItem("test"))  //test
		localStorage2.removeItem('test')
		console.log(localStorage2.getItem("test"))  //null
		localStorage2.setItem('test', 'test')
		localStorage2.clear()
		console.log(localStorage2.getItem("test"))  //null