flat-array.js

//implementation

/**
 * @name    	flatten
 * @brief   	flatten an array of arbitrarily nested arrays of integers into a flat array of integers. 
 * @params	$array javascript array with no empty arrays allowed 
 * @return	flat array of integers
 * @example	[[1,2,[3]],4] -> [1,2,3,4]. 
 */
function flatten(array){
	var result = [];
	for(var element of array){
		if(Array.isArray(element))
			result = result.concat(flatten(element));
		else
			result.push(element);
  	}
	return result;
}

//Test
var nestedData = [[1,2,[3]],4];
var nestedPairsData = [[1,2,[3]],[4,5],3,[1,2],4];
var flatData = [1,2,3,4,5];

console.assert(JSON.stringify(flatten(nestedData)) == '[1,2,3,4]', 'error nestedData');
console.assert(JSON.stringify(flatten(nestedPairsData)) == '[1,2,3,4,5,3,1,2,4]', 'error nestedPairsData');
console.assert(JSON.stringify(flatten(flatData)) == '[1,2,3,4,5]', 'error flatData');