Underscore.js is a JavaScript library that provides a lot of useful functions that help in the programming in a big way like the map, filter, invoke, etc even without using any built-in objects.
The _.after() function is an inbuilt function in Underscore.js library of JavaScript which is used to create a wrapper of function which doesn’t do anything in the beginning but from the stated count it starts calling the stated function. Moreover, it is useful in a grouping of asynchronous responses, as you need to be sure if all the async calls have ended or not before preceding.
Syntax:
_.after(count, function)
Parameters: It accepts two parameters which are specified below:
- count: It is the number of counts after which the stated function will be called.
- function: It is the function stated.
Return values: This method returns the count of the function called.
Example 1:
<!DOCTYPE html> <html>   <head>     <script src=     </script> </head>   <body>     <script>         show = () => {             console.log("neveropen")         }         console.log(`Show function will run for 5 times:`)           // Calling after function         func = _.after(3, show);         func();         func();         func();         func();         func();         func();         func();     </script> </body>   </html> |
Output:
Show function will run for 5 times: neveropen neveropen neveropen neveropen neveropen
Example 2:
<!DOCTYPE html> <html>   <head>     <script src=     </script> </head>   <body>     <button id="button">button</button>     <script>         show = () => {             console.log("neveropen")         }           // Calling after function         func = _.after(3, show);         let button = document.querySelector("#button");         let Run = () => {             console.log(`Show function runs for 8 times:`)             for (let i = 0; i < 10; i++) {                 func();             }         }         button.addEventListener("click", Run)      </script> </body>   </html> |
Output:
button Show function runs for 7 times: neveropen neveropen neveropen neveropen neveropen neveropen neveropen neveropen
Here, you need to click on the button in order to see the output.
Reference: https://underscorejs.org/#after
