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:
<!DOCTYPE html>
<html>
<head>
<script src=
"https://unpkg.com/underscore@1.11.0/underscore-min.js">
</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:
<!DOCTYPE html>
<html>
<head>
<script src=
"https://unpkg.com/underscore@1.11.0/underscore-min.js">
</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