Underscore.js Introduction

Underscore.js is a concise, easy-to-use, and efficient JavaScript library that provides over 100 functions covering various data types and operations, including arrays, objects, functions, strings, numbers, and dates. Underscore.js is renowned for its simplicity, ease of use, and efficiency, making it widely adopted in numerous JavaScript projects.

Key Features of Underscore.js

• Conciseness: Underscore.js functions are highly concise, making them easy to understand and use.
• Ease of Use: Underscore.js functions follow a consistent naming convention and are well-documented, enabling get started quickly.
• Efficiency: Underscore.js functions are meticulously optimized to ensure efficient execution.
• Extensive Applicability: Underscore.js is extensively used in a wide range of JavaScript projects, including jQuery, Backbone.js, and AngularJS.

Core Functions of Underscore.js

Underscore.js offers an extensive collection of over 100 functions covering various data types and operations, including arrays, objects, functions, strings, numbers, and dates. Some of the most commonly used functions include:

• Array Functions: Underscore.js provides a comprehensive set of array functions to effortlessly manipulate arrays, including each(), map(), filter(), reduce(), find(), findIndex(), sort(), and shuffle().
• Object Functions: Underscore.js offers a range of object functions to conveniently work with objects, such as keys(), values(), pairs(), pick(), omit(), extend(), and defaults().
• Function Functions: Underscore.js provides a collection of function functions to seamlessly operate on functions, including bind(), debounce(), throttle(), once(), and memoize().
• String Functions: Underscore.js offers a variety of string functions to effortlessly manipulate strings, such as trim(), stripTags(), escape(), unescape(), capitalize(), and decapitalize().
• Number Functions: Underscore.js provides a set of number functions to conveniently work with numbers, including abs(), ceil(), floor(), round(), max(), and min().
• Date Functions: Underscore.js offers a range of date functions to effortlessly manipulate dates, such as now(), format(), parse(), add(), and subtract().

Usage of Underscore.js

Underscore.js can be utilized in various ways. The simplest method is to directly include the Underscore.js library in your HTML page, allowing you to use Underscore.js functions. For instance, you can use the following code to employ Underscore.js’s each() function to iterate through an array:

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.3/underscore-min.js"></script>
<script>
  var numbers = [1, 2, 3, 4, 5];
  _.each(numbers, function(number) {
    console.log(number);
  });
</script>

Alternatively, you can use Underscore.js’s AMD or CommonJS modules to load the Underscore.js library. For example, you can use the following code to utilize Underscore.js’s AMD module:

define(['underscore'], function(_) {
  var numbers = [1, 2, 3, 4, 5];
  _.each(numbers, function(number) {
    console.log(number);
  });
});

Alternatives to Underscore.js

Underscore.js is a highly popular JavaScript library, but it is not the only option available. Several other JavaScript libraries offer similar functionalities, including:

• Lodash: Lodash is a fork of Underscore.js that provides more functions and enhanced capabilities.
• Ramda: Ramda is a functional programming library that offers more concise and expressive functions.
• Prototype.js: Prototype.js is a veteran JavaScript library that provides functionalities similar to Underscore.js, but it is no longer actively maintained.

Conclusion

Underscore.js is a widely adopted JavaScript library that offers over 100 functions covering various data types and operations, including arrays, objects, functions, strings, numbers, and dates. Underscore.js stands out for its simplicity, ease of use, and efficiency, making it a popular choice in numerous JavaScript projects.

GitHub - jashkenas/underscore: JavaScript's utility _ belt