It is a function that helps in making things much easier. It allows the users to periodically “poll” the server and ask for fresh information. The server simply responds and sends fresh information to the client. The best is that the whole process is automatic which makes sure that the users need not gave to manually check for the updates.
This function allows the developer to run a given functionality for a single time. 'once' runs for a single time for the page without running again for that same page which is beneficial in avoiding duplicate initialization. 'once' is used for calling a function and not at the time of defining the function. Most importantly, ‘once’ can be used with any of the existing functions including those that are in the external libraries.
Many times, the developers need to validate a value by asking users for the purpose of confirming that the input was submitted. Thus, they require to display the values as string irrespective of their types of data. The 'toString' function is used with a number of objects for displaying their values as character.
At the time of designing a website, developers frequently require the users for inputting a specific value prior accessing the web page. This pre-built function plays a crucial role in helping the programmers by prompting the users to ask an input value with the help of a prompt box. Now, the users require to enter the value and click ‘OK’ or ‘CANCEL’ button for accessing the web page without which it is not possible.