Flattens an array of arbitrarily nested arrays

FlattenArray.js

// Flattens an array of arbitrarily nested arrays
function flattenArray(inputArray) {
	var flattenedArray = []
	
	inputArray.forEach(function(value) {
		if (value instanceof Array) {
			// Concat the flattened value if it is an array
			flattenedArray = flattenedArray.concat(flatten(value))
		} else {
			// Push the raw value
			flattenedArray.push(value)
		}
	})
	
	return flattenedArray
}

var nestedArray = [[1,2,[3]],4]

// Log the result of the flattenArray function using nestedArray
console.log(flattenArray(nestedArray))