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 _.iteratee() function is an inbuilt function in Underscore which is used to generate a callback that can be applied to every element in a collection. This method supports multiple shorthand syntaxes for common callback use cases and returns the output depending on the type of the value.
Syntax:
_.iteratee( value, context )
Parameters: This method accepts two parameters as mentioned above and described below:
- value: It is the stated value.
- context: It is the context to be used. It is an optional parameter.
Return Value: This method returns the output depending on the type of value.
Example 1: In this example, no parameter is used with the method.
HTML
<!DOCTYPE html> <html>   <head>     <script src=     </script> </head>   <body>     <script type="text/javascript">           // Calling iteratee method with         // no parameters         console.log(_.iteratee());     </script> </body>   </html> |
Output:
function(n){return n}
Example 2: In this example, a user-defined function is given to the method.
HTML
<!DOCTYPE html> <html>   <head>     <script src=     </script> </head>   <body>     <script type="text/javascript">           // Calling iteratee method         // with its parameter         console.log(             _.iteratee(                 function (num) {                     return num * 4;                 }             )         );     </script> </body>   </html> |
Output:
function(num) { return num * 4; }
Example 3: In this example, a key-value pair is passed as the parameter.
HTML
<!DOCTYPE html> <html>   <head>     <script src=     </script> </head>   <body>     <script type="text/javascript">           // Calling iteratee method         // with its parameter         console.log(             _.iteratee(                 { portal: 'neveropen' }, []             )         );     </script> </body>   </html> |
Output:
function(n){return h.isMatch(n,r)}
Example 4: In this example, a string is passed as the parameter.
HTML
<!DOCTYPE html> <html>   <head>     <script src=     </script> </head>   <body>     <script>           // Calling iteratee method with         // its parameter         console.log(             _.iteratee('GfG', [])         );     </script> </body>   </html> |
Output:
function(n){return null==n?void 0:n[r]}
