Lodash _.over() Method

Syntax, Parameter and Return Value

Syntax: 

_.over([iteratees=[_.identity]])

Parameters:

[iteratees=[_.identity]] (...(Function|Function[])): The functions to invoke.

Return Value: 

(Function) - Returns the new function.

Examples 

Applying Multiple Validations:

• JavaScript

JavaScript

var _ = require('lodash');

var isEven = n => n % 2 === 0;

var isPositive = n => n > 0;

var checkNumber = _.over([isEven, isPositive]);

console.log(checkNumber(4));

console.log(checkNumber(-3));

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Output: 

[true, true]
[false, false]

Demonstrates using _.over() to apply multiple validation functions to a single input.

Aggregating Multiple Transformations:

• JavaScript

JavaScript

var double = n => n * 2;

var square = n => n * n;

var transform = _.over([double, square]);

console.log(transform(5));

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Output:

 [10, 25]

Shows applying multiple transformation functions to the same input.

Combining Data Analysis Functions:

• JavaScript

JavaScript

var average = arr => _.sum(arr) / arr.length;

var max = arr => _.max(arr);

var min = arr => _.min(arr);

var analyzeNumbers = _.over([average, max, min]);

console.log(analyzeNumbers([1, 2, 3]));

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Output:

 [2, 3, 1]

An example of using _.over() to perform multiple data analysis operations on an array.

Conditional Function Execution:

• JavaScript

JavaScript

var greet = name => 'Hello, ' + name;

var farewell = name => 'Goodbye, ' + name;

var greetOrFarewell = _.over([greet, farewell]);

console.log(greetOrFarewell('Alice'));

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Output: 

['Hello, Alice', 'Goodbye, Alice']

Demonstrates conditional execution of different functions based on the same input.

Frequently Asked Questions

How does _.over() differ from _.flow() or _.flowRight()?

While _.flow() and _.flowRight() compose functions in a sequence (the output of one function is the input to the next), _.over() applies all functions to the same input independently and aggregates their results.

Can _.over() handle asynchronous functions?

_.over() is designed for synchronous functions. For asynchronous functions, you would need to handle promises or async/await patterns.

Is _.over() efficient for large arrays or complex functions?

The efficiency of _.over() depends on the complexity of the functions involved and the size of the input data. For computationally intensive tasks or large datasets, performance considerations may require optimized or parallelized approaches.

Conclusion

Lodash's _.over() method is a powerful tool for combining multiple functions to be applied to the same set of inputs, providing a straightforward way to aggregate results from diverse operations. It's particularly useful for scenarios requiring parallel function execution and result aggregation in data processing and validation tasks.

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