Code to see if an array of a sudoku number set is valid.

compare3x3.js

function compare3x3(data) {

	"use strict";

	var chunkLength = data.length / 3,
		iter = 1,
		objarr = {
			"array1": [],
			"array2": [],
			"array3": [],
			"array4": [],
			"array5": [],
			"array6": [],
			"array7": [],
			"array8": [],
			"array9": []
		};

	for (var i = 0; i < 3; i++) {
		var chunk = data.slice(i * chunkLength, chunkLength * (i + 1));

		var iter = 1;

		for (var j = 0; j < chunkLength; j += 3) {

			var t1 = chunk[j],
				t2 = chunk[j + 1],
				t3 = chunk[j + 2];

			if (iter === 4) {
				iter = 1;
			}

			objarr["array" + ((i * 3) + iter)].push(t1);
			objarr["array" + ((i * 3) + iter)].push(t2);
			objarr["array" + ((i * 3) + iter)].push(t3);

			iter++;
		}
	}

	for (var k in objarr) {
		var arrayhold = objarr[k].sort();

		for (var l = 0; l < arrayhold.length; l++) {
			if (arrayhold[l + 1] === arrayhold[l]) {
				return k;
			}
		}
		return true;
	}
}

module.exports = compare3x3;

comparecolumns.js

function compareColumns(data) {
	
	for (var i = 0; i < 9; i++) {
		
		var arrayHold = [];
		
		for (var j = 0; j < 9; j++) {
			arrayHold.push(data[i + (9 * j)]);
		}

		var temp = arrayHold.sort();
		
		for (var k = 0; k < temp.length; k++) {
			if (temp[k + 1] === temp[k]) {
				return i+1;
			}
		}
		return true;
	}
}

module.exports = compareColumns;

comparerows.js

function compareRows(data) {
	
	var temp,
		chunk = 9;

	for (var i = 0; i < data.length; i+= chunk) {
		
		temp = data.slice(i, i + chunk);
		
		var tempArray = temp,
			sortedArr = tempArray.sort();

		for (var j = 0; j < sortedArr.length; j++) {
			
			if (sortedArr[j + 1] === sortedArr[j]) {
				return i+1;
			} 
		}
		
		return true;
	}
};

module.exports = compareRows;

sudokupuzzle.js

var compareRows = require('./comparerows.js'),
	compareColumns = require('./comparecolumns.js'),
	compare3x3 = require('./compare3x3.js'),
	linesTrue = [8,9,5,7,4,2,1,3,6,2,7,1,9,6,3,4,8,5,4,6,3,5,8,1,7,9,2,9,3,4,6,1,7,2,5,8,5,1,7,2,3,8,9,6,4,6,8,2,4,5,9,3,7,1,1,5,9,8,7,4,6,2,3,7,4,6,3,2,5,8,1,9,3,2,8,1,9,6,5,4,7];

var verifyRows = compareRows(linesTrue),
	verifyColumns = compareColumns(linesTrue),
	verify3x3 = compare3x3(linesTrue);

if (verifyColumns === true && verifyRows === true && verify3x3 === true) {
	process.stdout.write("This sudoku set is true");
} else {
	console.log("Error in Column " + verifyColumns);
	console.log("Error in Row " + verifyRows);
	console.log("Error in 3x3 " + verify3x3);
	process.stdout.write("This sudoku set is all lies!");
}