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 _.uniqueId() function is an inbuilt function in Underscore.js library of JavaScript which is used to generate a globally unique id for the client-side models or the DOM elements which requires one. When a prefix is passed as an argument to this method, the id generated will be appended to it.
Syntax:
_.uniqueId( prefix )
Parameters: It accepts a single parameter as mentioned above and described below:
- prefix: It is the prefix that would be appended to the id It is am optional parameter.
Return Value: This method returns a globally unique id.
Example 1:
HTML
<!DOCTYPE html> < html >   < head >     < script src =     </ script > </ head >   < body >     < script type = "text/javascript" >           // Using _.uniqueId() method         // with its parameter         console.log(_.uniqueId('gfG_'));         console.log(_.uniqueId('Geeks_'));         console.log(_.uniqueId('CS_'));     </ script > </ body >   </ html > |
Output:
gfG_1 Geeks_2 CS_3
Example 2:
HTML
<!DOCTYPE html> < html >   < head >     < script src =     </ script > </ head >   < body >     < script type = "text/javascript" >           // Using a loop         for (i = 3; i < 100 ; i *= 2) {               // Calling uniqueId method             // without any parameter               console.log(_.uniqueId());         }     </script> </ body >   </ html > |
Output:
1 2 3 4 5 6