[1,2,3].CONTAINS([1,2]) ==> true
[1,2,3].CONTAINS([1,2,3,4]) ==> false
or
{a:1,b:2,c:3}.HASKEYS([a,b]) ==> true
{a:1,b:2,c:3}.HASKEYS([a,b,c,d]) ==> false
Is there a single function to check an array contains another array?
No, but you can make one:
Array.prototype.contains = function(other) {
for (var i = 0; i < other.length; i++) {
if (this.indexOf(other[i]) === -1) return false;
}
return true;
}
And if order matters:
Array.prototype.contains = function(other) {
var broken;
if (!other.length) return true;
for (var i = 0; i < this.length - other.length + 1; i++) {
broken = false;
for (var j = 0; j < other.length; j++) {
if (this[i + j] !== other[j]) {
broken = true;
break;
}
}
if (!broken) return true;
}
return false;
}
The other function is similar, so I'll leave it to you to finish:
Object.prototype.has_keys = function(keys) {
...
}
Related
in hasValue class, why return is not working? when i try with console.log and alert, it worked.
want to implement function like priorityQueue.changePriority("Sheru", 1); changePriority class is not working.
commented code is code i tried to implement the changes i.e. i want to change the priority of existing item present in queue. Could anyone please help?
class QElement {
constructor(element, priority) {
this.element = element;
this.priority = priority;
}
}
class PriorityQueue {
constructor() {
this.items = [];
}
isEmpty() {
return this.items.length == 0;
}
add(element, priority) {
var qElement = new QElement(element, priority);
var contain = false;
for (var i = 0; i < this.items.length; i++) {
if (this.items[i].priority > qElement.priority) {
this.items.splice(i, 0, qElement);
contain = true;
break;
}
}
if (!contain) {
this.items.push(qElement);
}
}
peek() {
if (this.isEmpty())
return "No elements in Queue";
return this.items[0];
}
poll() {
if (this.isEmpty())
return "Underflow";
return this.items.shift();
}
/*changePriority(firstTerm, secondTerm)
{
let xxx = new QElement(firstTerm, secondTerm);
for (let i = 0; i < this.items.length; i++){
if (this.items[i].element === firstTerm){
this.items[i].priority = secondTerm;
this.items.splice(i, 0, xxx);
}
}
this.items.push(xxx);
}*/
hasValue(args) {
let status = false;
for (let i = 0; i < this.items.length; i++) {
if (this.items[i].element === args) {
status = true;
}
}
console.log(status);
}
size() {
if (this.isEmpty())
return "Underflow";
return this.items.length;
}
printPQueue() {
var str = "";
for (var i = 0; i < this.items.length; i++)
str += this.items[i].element + " ";
return str;
}
}
var priorityQueue = new PriorityQueue();
console.log(priorityQueue.isEmpty());
console.log(priorityQueue.peek());
priorityQueue.add("Sumit", 2);
priorityQueue.add("Gourav", 1);
priorityQueue.add("Piyush", 1);
priorityQueue.add("Sunny", 2);
priorityQueue.add("Sheru", 3);
console.log(priorityQueue.printPQueue());
console.log(priorityQueue.peek().element);
console.log(priorityQueue.poll().element);
priorityQueue.add("Sunil", 2);
console.log(priorityQueue.size());
priorityQueue.hasValue('Sumit');
console.log(priorityQueue.printPQueue());
priorityQueue.changePriority("Sheru", 1);
console.log(priorityQueue.printPQueue());
You missing return keyword. This just works:
hasValue(args) {
for (let i = 0; i < this.items.length; i++) {
if (this.items[i].element === args) {
return true;
}
}
return false;
}
I did not understand the idea how your changePriority function should work. Just find the element and move it up or down based on priority change:
swap(a, b) {
let tmp = this.items[a];
this.items[a] = this.items[b];
this.items[b] = tmp;
}
changePriority(firstTerm, secondTerm) {
let i = 0;
while (i < this.items.length) {
if (this.items[i].element === firstTerm) {
if (secondTerm < this.items[i].priority) {
// move up
this.items[i].priority = secondTerm;
while (i > 0 && this.items[i - 1].priority > secondTerm) {
this.swap(i - 1, i);
i--;
}
} else if (secondTerm > this.items[i].priority) {
// move down
this.items[i].priority = secondTerm;
while (i < this.items.length - 1 && this.items[i + 1].priority < secondTerm) {
this.swap(i + 1, i);
i++;
}
}
break;
}
i++;
}
}
How can you refactor this function? I feel like a nested for loop would work but I haven't figured out how to make it work.
Here's the function:
class Librarian {
constructor(name, library) {
this.name = name;
this.library = library;
}
findBook(bookTitle) {
for (var i = 0; i < this.library.shelves.fantasy.length; i++){
if (bookTitle === this.library.shelves.fantasy[i].title){
this.library.shelves.fantasy.splice(i, 1);
return `Yes, we have ${bookTitle}`;
}
} for (var i = 0; i < this.library.shelves.fiction.length; i++){
if (bookTitle === this.library.shelves.fiction[i].title){
this.library.shelves.fiction.splice(i, 1);
return `Yes, we have ${bookTitle}`;
}
} for (var i = 0; i < this.library.shelves.nonFiction.length; i++){
if (bookTitle === this.library.shelves.nonFiction[i].title){
this.library.shelves.nonFiction.splice(i, 1);
return `Yes, we have ${bookTitle}`;
}
} return `Sorry, we do not have ${bookTitle}`;
}
}
Here's my attempt:
findBook(bookTitle) {
for (var j = 0; j < this.libray.shelves.length; j++) {
for (var i = 0; i < this.library.shelves[i].length; i++){
if (bookTitle === this.library.shelves[j].title){
this.library.shelves[j].splice(i, 1);
return `Yes, we have ${bookTitle}`;
}
}
} return `Sorry, we do not have ${bookTitle}`;
}
Get the genres' names and then loop over them:
findBook(bookTitle) {
const genres = Object.keys(this.library.shelves);
for (var i = 0; i < genres.length; i++) {
const genre = genres[i];
for (var j = 0; j < this.library.shelves[genre].length; j++) {
if (bookTitle === this.library.shelves[genre][j].title) {
this.library.shelves[genre].splice(i, 1);
return `Yes, we have ${bookTitle}`;
}
}
}
return `Sorry, we do not have ${bookTitle}`;
}
It looks like you're really close to getting this to work, you just need to iterate over this.library.shelves[j].length in the second for loop instead of i. Then you need to access the ith member of the jth shelf.
findBook(bookTitle) {
for (var j = 0; j < this.libray.shelves.length; j++) {
for (var i = 0; i < this.library.shelves[j].length; i++){
if (bookTitle === this.library.shelves[j][i].title){
this.library.shelves[j].splice(i, 1);
return `Yes, we have ${bookTitle}`;
}
}
}
return `Sorry, we do not have ${bookTitle}`;
}
I'm currently stuck on a problem. I'm trying to make [[1,2,[3]],4] -> [1,2,3,4] but cannot get it to work. The output I keep getting is: 1,2,3,4
1,2,3
3
3
3
3..........3
function flattenArray(input) {
var result = [];
console.log(input.toString());
for(i = 0; i < input.length; i++) {
if(input[i].constructor === Array) {
result.push(flattenArray(input[i]));
} else {
result.push(input[i]);
}
}
return result;
}
console.log(flattenArray([[1,2,[3]],4]));
I have this in my common.js file. I use it all the time.
Array.prototype.flatten = function () {
var ret = [];
for (var i = 0; i < this.length; i++) {
if (Array.isArray(this[i])) {
ret = ret.concat(this[i].flatten());
} else {
ret.push(this[i]);
}
}
return ret;
};
Here it is as a function:
function flattenArray(input) {
console.log(input.toString());
var ret = [];
for (var i = 0; i < input.length; i++) {
if (Array.isArray(input[i])) {
ret = ret.concat(flattenArray(input[i]));
} else {
ret.push(input[i]);
}
}
return ret;
}
I have a rzslider which takes in true or false for disabled. I want disable to be true based on a function. So I want to make it disabled:$scope.truthy
I have a function called checkDupsName() checkDupsName should return true if there is a duplicate, false otherwise. I set my $scope.truthy variable to be true if the function returns true but the issue is, when I call it outside this function ( in my slider), it's ALWAYS false.
$scope.checkDupsName = function(Mylist) {
var i, j, n;
n = Mylist.length;
for (i = 0; i < n; i++) {
for (j = i + 1; j < n; j++) {
if (Mylist[i] === Mylist[j]) {
return true;
}
}
}
return false;
};
$scope.truthy=false;
$scope.nameList = [];
var Types = [];
$scope.loadRuleList = function() {
PrioritizeService.getData($scope.prioritizeURL).
then(function(response) {
if (response) {
Types = response;
}
for (var k = 0; k < Types.length; k++) {
$scope.nameList.push(Types[k].name);
}
if($scope.checkDupsName($scope.nameList)) {
$scope.truthy=true;
}
};
$scope.slider = {
value: 1,
options: {
floor: 0,
ceil: 3,
showTicks: true,
showTicksValues: true,
disabled:$scope.truthy
}
};
You are defining it inside of your function that is being called by then. You should move it outside and make it a function defined/declared on the scope instead and have it take the data it uses as a parameter.
// initialize it so your code does not blow up in the case of forgotten undefined or null check
$scope.nameList = [];
$scope.loadRuleList = function() {
var me = this;
PrioritizeService.getData($scope.MyURL).
then(function(response) {
if (response) {
Types = response;
}
// re-init the nameList field
me.nameList = [];
for (var k = 0; k < Types.length; k++) {
me.nameList.push(Types[k].name)
}
//check for duplicates
var areDups = me.checkDupsName(me.nameList);
}
}
$scope.checkDupsName = function(listToCheck) {
var i, j, n;
n = listToCheck.length;
for (i = 0; i < n; i++) {
for (j = i + 1; j < n; j++) {
if (listToCheck[i] === listToCheck[j]) {
return true;
}
}
}
return false;
}
This code is designed to identify an array of anagrams for a string given an array of possible anagrams.
var anagram = function(input) {
return input.toLowerCase();
}
I'm adding the matcher function here to the String prototype.
String.prototype.matcher = function(remainingLetters) {
var clone = this.split("");
for (var i = 0; i < clone.length; i++) {
if (clone[i].indexOf(remainingLetters) > -1) {
remainingLetters.splice(clone[i].indexOf(remainingLetters, 1));
clone.splice(i, 1);
}
}
if (remainingLetters.length == 0 && clone.length == 0) {
return true;
}
else {
return false;
}
}
a
String.prototype.matches = function(matchWordArray) {
var result = [];
for (var i = 0; matchWordArray.length; i++) {
var remainingLetters = this.split("");
if (matchWordArray[i].matcher(remainingLetters)) {
result.push(arrayToMatch[i]);
}
}
return result;
}
var a = anagram("test");
a.matches(["stet", "blah", "1"]);
module.exports = anagram;
Should probably be:
for (var i = 0; i < matchWordArray.length; i++) {
The original statement:
for (var i = 0; matchWordArray.length; i++) {
...would result in an infinite loop because matchWordArray.length is always truthy (3) in your test.