Develop Reference

No response from recursive function

I want to create a function that is able to determine if a number is same or palindrome. if a given number is palindrome or same then return 2 otherwise if it is not palindrome or same then i need check it twice by increment the given number by 1. after that if it palindrome or same then return 1. if no palindrome or same number found then return 0. i write the function which is giving me the exact result when i give the number as 11211 but the function don't show any response if i enter 1122 or other random value. please help me to find where the error of my function.
function sameOrPalindrome(num) {
var c = 0;
var al = 0;
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse();
for (var i = 0; i < normalArray.length; i++) {
if (normalArray[i] != revArray[i]) {
c++;
}
}
if (c == 0) {
return 2;
} else {
num++;
al = sameOrPalindrome(num);
if (al == 2) {
return 1;
} else {
num++;
al = sameOrPalindrome(num);
if (al == 2) {
return 1;
}
}
}
return 0;
}
console.log("1233",sameOrPalindrome(1233))

here is my solution to this problem:
function reversedNum(num) {
return (
parseFloat(
num
.toString()
.split('')
.reverse()
.join('')
) * Math.sign(num)
)
}
function sameOrPalindrome(num) {
if (num === reversedNum(num)) {
return 2;
} else {
num++;
if (num === reversedNum(num)) {
return 1;
} else {
num++;
if (num === reversedNum(num)) {
return 1;
}
}
}
return 0;
}
console.log("1233",sameOrPalindrome(1233))

Perhaps not using recurse - I think your function loops
const allEqual = arr => arr.every( v => v === arr[0] )
const sameOrPalin = num => {
const str = String(num);
let arr = str.split("")
if (allEqual(arr)) return 2
arr.reverse();
if (arr.join("") === str) return 1;
return 0
};
console.log("1111",sameOrPalin(1111));
console.log("2111",sameOrPalin(2111));
console.log("2112",sameOrPalin(2112));
console.log("1234",sameOrPalin(1234));
for (let i = 2111; i<=2113; i++) console.log(i,sameOrPalin(i));

Question: I assumed if palindrome test is true at first time then return 2. if not try incrementing by one and test the palindrome again . if true return 1 else try incrementing for last time and check the palindrome if true return 1 else 0.
Store string into array first and do arr.reverse().join("") to compare
let arr=num.toString().split("");
if(num.toString() == arr.reverse().join(""))
function sameOrPalindrome(num, times) {
let arr = num.toString().split("");
if (num.toString() == arr.reverse().join("")) {
if (times == 3) return 2
else return 1;
} else if (times > 0) {
num++; times--;
return sameOrPalindrome(num, times);
} else return 0
}
console.log(sameOrPalindrome(123321, 3));
console.log(sameOrPalindrome(223321, 3));
console.log(sameOrPalindrome(323321, 3));

Your function needs to know if it should not call itself any more, e.g. when it's doing the second and third checks:
function sameOrPalindrome(num,stop) { // <-- added "stop"
var c = 0;
var al = 0;
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse();
for (var i = 0; i < normalArray.length; i++) {
if (normalArray[i] != revArray[i]) {
c++;
}
}
if (c == 0) {
return 2;
} else if(!stop) { // <-- check of "stop"
num++;
al = sameOrPalindrome(num,true); // <-- passing true here
if (al == 2) {
return 1;
} else {
num++;
al = sameOrPalindrome(num,true); // <-- and also here
if (al == 2) {
return 1;
}
}
}
return 0;
}
for(let i=8225;i<8230;i++)
console.log(i,sameOrPalindrome(i));

function check_palindrom(num){
var c1 = 0;
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse();
for (var i = 0; i < normalArray.length; i++) {
if (normalArray[i] == revArray[i]) {
c1++;
}
}
if(c1==0){
return 2;
}else{
return 1;
}
}//check_palindrom
function my_fun_check_palindrome(mynum){
//console.log(mynum);
var num = mynum;
var c2 = 0;
var al = 0;
var normalArray = mynum.toString().split("");
var revArray = mynum.toString().split("").reverse();
for (var j = 0; j < normalArray.length; j++) {
if (normalArray[j] == revArray[j]) {
c2++;
}
}
if(c2==0){
console.log('Number is palindrome. Return Value :'+ 2);
}
if(1){
console.log('checking again with incremeting value my one');
num = parseInt(num)+1;
al = check_palindrom(num);
if(al==2){
console.log('Number is palindrome. Return Value :'+ 1);
}else{
console.log('Number is not palindrome. Return Value :'+ 0);
}
}
}//my_fun_check_palindrome
console.log(my_fun_check_palindrome(1122));
console.log(my_fun_check_palindrome(11221));

We should always strive to make function more effiecient... you dont need to run full loop. plus actual checking of palindrome can me modularized
function isSameOrPalindrome(num) {
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse(),
i;
for (i = 0; i < normalArray.length / 2; i++) {
if (normalArray[i] !== revArray[i]) {
break;
}
}
if (i >= normalArray.length/2) {
return "Palindrome";
} else {
return "Not Palindrome";
}
}
function doCheck(num) {
var isPalindrome = isSameOrPalindrome(num);
console.log(isPalindrome);
if(isPalindrome === "Palindrome") {
return 2;
} else {
num++;
isPalindrome = isSameOrPalindrome(num);
if(isPalindrome === "Palindrome") {
return 1;
} else {
return 0
}
}
}
console.log("100",doCheck(100));

JavaScript Recursive function return undefined instead of an array

I have the next function:
function solveSudoku(prev_tab, fila, columna) {
let tab = _.cloneDeep(prev_tab);
let sig_fila = fila;
let sig_col = columna;
if (fila === 8 && columna === 8) {
//console.log(tab);
return tab;
}
if (columna === 8) {
sig_col = 0;
sig_fila = sig_fila + 1
} else {
sig_col = sig_col + 1;
}
if ((tab[fila][columna]) !== '') {
solveSudoku(tab, sig_fila, sig_col)
} else {
for (let num = 1; num <= 9; num++) {
if (numeroValido(tab, num, fila, columna)) {
tab[fila][columna] = num;
//tab.toString();
solveSudoku(tab, sig_fila, sig_col)
}
}
}
}
it returns undefined instead of a 2D array, i already try to add return in every recursive call =>
return solveSudoku( tab, sig_fila, sig_col )
but now that doesn't work either

I'm not really familiar with algorithms for solving sudoku, so I don't know if the algorithm below is correct.
But you need to ensure that the result of the recursion is returned. In my update below, I return the first recursive call. In the loop, I only return it if the recursion successfully found a solution, otherwise the loop continues trying other numbers in the column.
function solveSudoku(prev_tab, fila, columna) {
let tab = _.cloneDeep(prev_tab);
let sig_fila = fila;
let sig_col = columna;
if (fila === 8 && columna === 8) {
//console.log(tab);
return tab;
}
if (columna === 8) {
sig_col = 0;
sig_fila = sig_fila + 1
} else {
sig_col = sig_col + 1;
}
if ((tab[fila][columna]) !== '') {
return solveSudoku(tab, sig_fila, sig_col)
} else {
for (let num = 1; num <= 9; num++) {
if (numeroValido(tab, num, fila, columna)) {
tab[fila][columna] = num;
//tab.toString();
let result = solveSudoku(tab, sig_fila, sig_col);
if (result) { // continue searching if the recursion failed
return result;
}
}
}
}
}

How do I get a toggle button to toggle an array back and forth from descending to ascending?

I am using bubbleSort, and I can get the array to toggle from its original order to descending, but I am having trouble getting it to go from descending back to ascending. Should I just copy the bubbleSort code and flip the greater than/less than signs? Any help is appreciated!
var myStuff = [];
function myfunctionA() {
var enteredvalue = document.getElementById("numbers").value;
// alert(typeof Number(document.getElementById('numbers').value));
if (enteredvalue == "") {
alert("Input is not a number");
} else if (isNaN(enteredvalue)) {
alert('You need to enter a valid number!');
}
var elementExists = false;
var x = document.getElementById('numbers').value;
for (var i = 0; i < myStuff.length; i++) {
if (myStuff[i] == Number(x)) {
elementExists = true;
}
}
if(elementExists != true) {
myStuff.push(Number(enteredvalue));
alert('Thank You for entering a valid number.');
} else {
alert('Element is here');
}
}
function myfunctionB() {
window.alert(myStuff.length);
}
function myfunctionC() {
var sum = 0;
for(var i = 0; i < myStuff.length; i++) {
sum+=myStuff[i];
}
alert(sum);
}
function myfunctionD() {
if (myStuff.length == 0) {
alert("already empty");
} else {
myStuff = [];
}
alert("Array Empty");
}
function myfunctionE() {
alert(myStuff.join('\n'));
{
if (myStuff == []) {
alert("Enter something into Array")
}
}
}
function bubbleSort() {
var sorted = true;
var temp;
while(sorted) {
sorted = false;
for(var i = 0; i < myStuff.length-1; i++) {
if(myStuff[i] < myStuff[i+1]) {
temp = myStuff[i];
myStuff[i] = myStuff[i+1];
myStuff[i+1] = temp;
sorted = true;
}
}
}
}

First you'll need a toggle to tell which way you are going.
var isAscending = false;
Then in your bubbleSort function inside the for-statement, above the if-statement.
var sortComparison;
if (isAscending) sortComparison = myStuff[i] > myStuff[i];
if (!isAscending) sortComparison = myStuff[i] < myStuff[i];
Then replace your if-statement with:
if (sortComparison)
Finally, once you have finished sorting, you can toggle your variable:
isAscending = !isAscending;
Though, I'd recommend using a toggled variable and simply using sort() and reverse() instead.
https://jsfiddle.net/ytcax0qc/

why two $scopes updates at the same time, duplicate data

I have this piece of code
$scope.addToOrder = function(index) {
var tempItem = $scope.item;
if (tempItem[index].validate == true){
if (_.isEmpty($scope.item2) == true) {
$scope.item2.push(tempItem[index]);
} else {
for (var i = 0; i < $scope.item2.length; i++) {
if ($scope.item2[i] == tempItem[index]) {
break;
}
if (i == $scope.item2.length - 1) {
$scope.item2.push(tempItem[index]);
}
}
}
}
}
I want to push data from one object to other (item to item2), it works well, but when i change data from item also item2 updates i dont want this.
What i missing?

As is, you are using an object reference. Then if modify one, the othes one is modified too.
You could use angular.copy
$scope.addToOrder = function(index) {
var tempItem = $scope.item;
var itemCopy = angular.copy(tempItem[index]);
if (tempItem[index].validate == true){
if (_.isEmpty($scope.item2) == true) {
$scope.item2.push(itemCopy);
} else {
for (var i = 0; i < $scope.item2.length; i++) {
if ($scope.item2[i] == tempItem[index]) {
break;
}
if (i == $scope.item2.length - 1) {
$scope.item2.push(itemCopy);
}
}
}
}
}

use angular.copy to cope by value
angular.copy($scope.item1, $scope.item2);
or
$scope.item1 = angular.copy($scope.item2);

Shortening if, else if, else if ... else using loops

I have the following lines of code:
$(function(){
$("div").scroll(function() {
function hpos(id) {
var pos = $("#" + id).position();
return pos.top;
}
function final(id) {
$("#header").html($("#" + id).html()),
$("h1").css("visibility","visible"),
$("#" + id).css("visibility","hidden");
}
if (hpos(5) < 0) {
final(5);
}
else if (hpos(4) < 0) {
final(4);
}
else if (hpos(3) < 0) {
final(3);
}
else if (hpos(2) < 0) {
final(2);
}
else {
final(1);
}
});
});
Shouldn't I be able to shorten it by using a loop instead of the else if statements? I can't find a way to make the loops work with my position().

for (var i = 5; i > 0; i--){
if (hpos(i) < 0) {
final(i);
break;
}
}
would something like this work? Not tested by the way

This should be shorter:
$.each([5,4,3,2], function(i,v) {
if( hpos(v) < 0 ) {
final(v);
return false;
} else if( v === 2 ) {
final(1);
}
});

An easier way to do lots of else if statements is to use the case method.

In case you need a while version:
:)
var elemId = 5;
while (elemId > 1) {
if (hpos(elemId) < 0) {
break;
}
elemId--;
}
final(elemId);