How to update local storage value in javascript
You’ve saved some data to Show
In today’s article, we’ll look at how to update Replacing localStorage() valuesLet’s say the name of your favorite sandwich is saved to
Your tastes have changed, and you want to change
it. You can replace the existing value by using
Appending data to a localStorage() stringWhat if you didn’t want to replace the existing value, but add a new item to it? First, we want to check if an existing item exists. If it does, we’ll use string concatenation to add our new item to the end of it. Otherwise, we’ll save the item as is. Note: In the example below, I’m using a ternary operator for brevity.
Appending data to a localStorage() arrayIf you’re storing collections of data, it might make more sense to use an array. Similar to the example above, we’ll first check to see if the item already exists. Then, we’ll push our new value to the array and save it back to
Appending data to a localStorage() objectDepending on what you’re doing, you might have your data saved as an object instead.
In this example, let’s add a drink to the We’ll again check to
see if the item exists already. If it does, we’ll use Then, we’ll push our new key/value pair to the object, and save it back to
Helper functionsThis time of thing is best handled with a helper function (not because it’s hard, but because it’s good to abstract this type of functionality out to keep your code more modular). Add to a string
Add to an array
Add to an object
How do I update localStorage values?Using localStorage object, we will invoke getItem('Key','Value') method to set data using localStorage. setItem('Key','Value') and change the button text using localStorage. getItem('Key').
Can we update localStorage?LocalStorage can only store strings, which is why you're stringifying your object before storing it. To manipulate the stored string as an object, you can pass it to JSON. parse (assuming it's properly JSON-formatted). Then to store the modified version, you need to convert it back into a string.
How does JavaScript handle local storage?To use localStorage in your web applications, there are five methods to choose from:. setItem() : Add key and value to localStorage.. getItem() : This is how you get items from localStorage.. removeItem() : Remove an item by key from localStorage.. clear() : Clear all localStorage.. Can JavaScript access local storage?There are four basic JavaScript methods you can use to access and work with localStorage: setItem() - takes a key-value pair and adds it to localStorage. getItem() - takes a key and returns the corresponding value. removeItem() - takes a key and removes the corresponding key-value pair.
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