Lodash _.isEqual() Method

Syntax, Parameter and Return Value

Syntax: 

_.isEqual(value, other)

Parameters:

• value: The value to compare.
   
• other: The other value to compare.

Return Value: 

(boolean) - Returns true if the values are equivalent, else false.

Examples 

Comparing Complex Objects:

• JavaScript

JavaScript

var _ = require('lodash');

var object1 = { a: 1, b: { c: 2 } };

var object2 = { a: 1, b: { c: 2 } };

console.log(_.isEqual(object1, object2)); 

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Output: 

true

Demonstrates the deep comparison of two objects with nested structures.

Checking Equality of Arrays:

• JavaScript

JavaScript

var array1 = [1, [2, 3]];

var array2 = [1, [2, 3]];

console.log(_.isEqual(array1, array2)); 

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 Output: 

true

Shows deep comparison of arrays, including nested arrays.

Differentiating Between Similar-looking Values:

• JavaScript

JavaScript

var obj1 = { a: 1, b: 2 };

var obj2 = { a: 1, b: '2' };

console.log(_.isEqual(obj1, obj2)); 

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Output: 

false

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An example of how _.isEqual() can differentiate between values that look similar but have different types.

Use in Conditional Logic:

function updateData(newData, oldData) {
  if (!_.isEqual(newData, oldData)) {
    // Perform update
  }
}

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Demonstrates using _.isEqual() in conditional logic to check if data has changed before performing an update.

Frequently Asked Questions

How does _.isEqual() handle circular references?

_.isEqual() can handle circular references in objects or arrays. It smartly tracks visited objects and arrays to avoid infinite loops in circular structures.

Is _.isEqual() efficient for large data structures?

While _.isEqual() is designed to be comprehensive, its deep comparison nature can be computationally intensive for very large or deeply nested structures. It should be used judiciously in performance-critical applications.

Can _.isEqual() compare function properties?

_.isEqual() compares function properties by reference, not by their internal structure or context. Two function properties are considered equal if they reference the same function.

Conclusion

Lodash's _.isEqual() method provides a robust solution for deep comparison of objects, arrays, and other complex data structures in JavaScript. It ensures accurate and comprehensive equality checks, far beyond what shallow comparison techniques can offer.

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