Syntax, Parameter and Return Value
Syntax:
_.round(number, [precision=0])
Parameters:
-
number (Number): The number to round.
- [precision=0] (Number): The precision to round to (number of decimal places).
Return Value:
(Number) - Returns the rounded number.
Examples
Rounding to Nearest Integer:
JavaScript
var _ = require('lodash');
console.log(_.round(4.006));

You can also try this code with Online Javascript Compiler
Run Code
Output:
4
Demonstrates rounding a number to the nearest integer.
Rounding with Precision:
JavaScript
console.log(_.round(4.006, 2));

You can also try this code with Online Javascript Compiler
Run Code
Output:
4.01
Shows rounding a number to a specified number of decimal places.
Use in Financial Calculations:
JavaScript
var amount = 1234.5678;
var roundedAmount = _.round(amount, 2); // Rounding to 2 decimal places for currency
console.log(roundedAmount);

You can also try this code with Online Javascript Compiler
Run Code
Output:
1234.57
An example of using _.round() in financial calculations to round currency amounts.
Application in Data Presentation:
JavaScript
var data = [1.12345, 2.34567, 3.98765];
var roundedData = data.map(num => _.round(num, 3));
console.log(roundedData);

You can also try this code with Online Javascript Compiler
Run Code
Output:
[1.123, 2.346, 3.988]
Demonstrates rounding an array of numbers for data presentation purposes.
Frequently Asked Questions
How does _.round() handle negative numbers?
_.round() rounds negative numbers in the same way as positive numbers, adhering to the specified precision.
Is _.round() suitable for all rounding needs?
_.round() is ideal for general-purpose rounding to a specified precision. For specific rounding methods (like always rounding up or down), other Lodash methods or native JavaScript functions might be more appropriate.
Can _.round() be used for large numbers or scientific calculations?
_.round() can be used for large numbers, but for scientific calculations requiring high precision, specialized libraries are recommended to handle floating-point arithmetic accurately.
Conclusion
Lodash's _.round() method provides a versatile and precise way to round numbers, accommodating various scenarios where control over rounding precision is important. It's a valuable tool for enhancing numerical accuracy and readability in calculations.
You can refer to our guided paths on the Coding Ninjas. You can check our course to learn more about DSA, DBMS, Competitive Programming, Python, Java, JavaScript, etc.
Also, check out some of the Guided Paths on topics such as Data Structure and Algorithms, Competitive Programming, Operating Systems, Computer Networks, DBMS, System Design, etc., as well as some Contests, Test Series, and Interview Experiences curated by top Industry Experts.