Underscore.js is a JavaScript library that makes operations on arrays, string, objects much easier and handy.
The _.identity() function is used to return the exact same replica of the value given to it as the argument. This function looks useless, but is used throughout Underscore as a default iteratee.
Note: It is very necessary to link the underscore CDN before going and using underscore functions in the browser. When linking the underscore.js CDN The “_” is attached to the browser as global variable.
Syntax:
_.identity( object );
Parameters: This function accepts single parameter object.
Return Value: This function returns the value of the given parameter.
Example 1:
JavaScript
<!DOCTYPE html> <html> <head> <script src= "https: //cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"> </script> </head> <body> <script> // Creating a string let str = new String("neveropen") // _.identity function of underscore.js let copystr = _.identity(str) console.log(`original string is ${str}`) console.log(`Identity string is ${copystr}`) </script> </body> </html> |
Output:
Example 2:
JavaScript
<!DOCTYPE html> <html> <head> <script src= "https: //cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"> </script> </head> <body> <script> // Creating a object let obj = { "a": 1, "b": 2, "c": 3 } // _.identity function of underscore.js let copyobj = _.identity(obj) console.log(`original object is ${obj}`) console.log(`Identity object is ${copyobj}`) // This will return true console.log(obj === copyobj) // Both objects are exactly same console.log("from obj : ", obj.a, " from copyobj: ", copyobj.a); // Made Changes in object obj.a = 12 // Change in one object // reflects in another console.log("change in one object" + " reflects in another =>") console.log("from obj : ", obj.a, " from copyobj: ", copyobj.a); </script> </body> </html> |
Output: