How Can I Persist Variables Across Page Loads in Web Applications?

Persist Variables Between Page Loads Using Web Storage

HTTP is stateless, so every time a page is reloaded, the variables and settings are reset to their initial values. To circumvent this limitation and maintain persistence between page loads, there are several techniques that can be employed.

Using Query Strings

In a form submission with the GET method, the URL gets updated with a query string. By setting a hidden input field in the form to a specific value, this value can be preserved through the query string.

On page load, JavaScript can extract this value from the query string and use it to determine the state of the page. However, this approach has limitations for passing larger sets of data.

Utilizing Web Storage

HTML5 introduced Web Storage, providing two types of storage: localStorage and sessionStorage. LocalStorage retains data indefinitely, while sessionStorage stores data only during the current browsing session.

To persist a variable, set it in sessionStorage on a suitable event, such as the button click event. On subsequent page loads, the value can be retrieved from sessionStorage.

Setting Cookies

Cookies provide another option for client-side data persistence. They are typically used for server-side data retrieval but can also be employed for client-side storage.

jQuery simplifies the process of setting and reading cookies. Setting a cookie on the button click event and reading it on page load will allow you to maintain the desired variable state. Remember to unset the cookie after use to prevent data persistence across sessions.

Other Methods

Window.name: This property can store strings and can persist across page refreshes and domains within the same tab. However, it is generally considered a less reliable method due to cross-domain limitations.

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