I have the following array containining values [8,0,7]. I would like to build a singly linked list for these array values, that is sequenced in the same order.
I have a ListNode object for each node in the linked list, which contains the value and a next link to the next node in the linked list. My code for building the linked list currently looks like this:
for(let i=0; i<results.length; i++){
console.log("n:",results[i])
if(!result){
result = new ListNode(results[i])
}else{
console.log("else",results[i])
result.next = new ListNode(results[i]);
}
}
For some reason the result linked list adds only 7 and not 0.
If I understand correctly, you're wanting to sequentially link ListNode objects by a single reference, in which case you'll need to update the result reference with the most recent ListNode() appended to the linked list, per iteration:
/* Added to support code snippet */
function ListNode(value) {
this.value = value;
this.next = '';
}
/* Input data */
const results = [8, 0, 7];
/* Track the latest list node appended to the linked list (ie, the head) */
let result = "";
for (let i = 0; i < results.length; i++) {
if (!result) {
result = new ListNode(results[i])
}
else {
result.next = new ListNode(results[i]);
console.log(`${result.value} -> ${result.next.value}`);
/* Update result reference to newly appended list node */
result = result.next
}
}
Another way to express this linking process more concisely would be via Array#reduce():
/* Added to support code snippet */
function ListNode(value) {
this.value = value;
this.next = '';
}
/* Reduce array to a linked list */
[8, 0, 7].reduce((prev, value) => {
/* Create node for current value */
const node = new ListNode(value);
/* If previous node exists, link it to current node */
if(prev) {
prev.next = node;
console.log(`${prev.value} -> ${node.value}`);
}
/* Return current node which will be the "previous" on
the next iteration */
return node;
}, "");
Related
I am using dexie.js, which is an indexDB wrapper. Anywhoo, I have an array that is called from the user's local storage, and my function is supposed to iterate through every list item in the DB and show it. However, upon clicking on my Butane it only shows the most recent input of name.
Note: You can see the entire database by adding a few values in and checking your local storage.
My JsFiddle:
https://jsfiddle.net/enzp3zws/1/
my html:
<ul id="mane"></ul>
my js:
var db = new Dexie("TestDatabase");
db.version(1).stores({
friends: '++id, name, age'
});
var collection = db.friends;
var placement = document.getElementById('rainman');
var jacement = document.getElementById('rainboy');
var stacement = document.getElementById('mane');
var listed = document.createElement('li');
function addrain(){
collection.each(function(friend){
var element = [friend.name];
for (var i = 0; i < element.length; i++){
listed.textContent = element[i];
document.getElementById('mane').appendChild(listed);
//alert(element); <-- this call alerts all names in database.
}
});
}
Please excuse the randomness of some of these variable names. I don't know what sleep is anymore.
You need to create a new 'li' element each time:
//Remove var listed = ... line in header, then:
function addrain(){
collection.each(function(friend){
var element = [friend.name];
for (var i = 0; i < element.length; i++){
var listed = document.createElement('li');
listed.textContent = element[i];
document.getElementById('mane').appendChild(listed);
}
//alert(element); <-- this call alerts all names in database.
});
}
The reason your code did not work before is that you only created one li element, and repeatedly changed its text and re-inserted it at different locations.
I am new to JS.
I set up a Saved Search in NetSuite that gives us the image fields (containing URLs) of our items. I am now setting up a script in NS which tests these fields to see what item fields return 404 (i.e. need to be fixed).
My question is, how to set up function imageURLValidator to iterate through the field values of function searchItems?
Below is my start to the process but obviously has much incorrect syntax.
function imageURLValidator() {
var searchResults = searchItems('inventoryitem','customsearch529');
var url = '';
var item = '';
var field = '';
//insert loop here to iterate over items in searchResults array
//loop through items
for (var i = 0, i > searchResults[inventoryObject].length, i++) {
item = searchResults.[inventoryObject].[i];
//loop through fields in item
for (var f = 2, f > item.length, f++) {
field = item[f];
//check URL via item field's value
var code = checkURL(item[field].getvalue([field]));
//generate error based on code variable
createErrorRecord(code,item,field)
}
}
}
function searchItems(type, searchid) {
//defining some useful variables that we will use later
var inventoryArray = [];
var count = 0;
//loading the saved search, replace the id with the id of the search you would like to use
var inventoryItemSearch = nlapiLoadSearch(type, searchid);
//run the search
var inventoryItemResults = inventoryItemSearch.runSearch();
//returns a js array of the various columns specified in the saved search
var columns = inventoryItemResults.getColumns();
//use a do...while loop to iterate through all of the search results and read what we need into one single js object
do {
//remember the first time through the loop count starts at 0
var results = inventoryItemResults.getResults(count, count + 1000.0);
//we will now increment the count variable by the number of results, it is now no longer 0 but (assuming there are more than 1000 total results) will be 1000
count = count + results.length;
//now for each item row that we are on we will loop through the columns and copy them to the inventoryObject js object
for (var i=0; i<results.length; i++){
var inventoryObject = {};
for (var j=0; j<columns.length; j++){
inventoryObject[columns[j].getLabel()] = results[i].getValue(columns[j]);
}
//then we add the inventoryObject to the overall list of inventory items, called inventoryArray
inventoryArray.push(inventoryObject);
}
//we do all of this so long as the while condition is true. Here we are assuming that if the [number of results]/1000 has no remainder then there are no more results
} while (results.length != 0 && count != 0 && count % 1000 == 0);
return inventoryArray;
}
function checkURL(url) {
var response = nlapiRequestURL(url);
var code = response.getCode();
return code;
}
function createErrorRecord(code,item,field) {
if (code == 404){
//create error record
var errorRecord = nlapiCreateRecord('customrecord_item_url_error');
errorRecord.setFieldValue('custrecord_url_error_item', item);
errorRecord.setFieldValue('custrecord_url_error_image_field', field);
}
}
Here I can see searchResults variable will be empty while looping. As your call to searchItems function is async. Which will take some time to execute because I guess it will fetch data from API. By the time it returns value, your loop also would have bee executed. You can test this by putting an alert(searchResults.length) or console.log(searchResults.length). For that you need to use callback function
Also even if you get the results in searchResults. The loop you are doing is wrong. The array you will get is like [{},{},{}] i.e. array of objects.
To access you'll need
for (var i = 0, i > searchResults.length, i++) {
var inventoryObject = searchResults[i] // your inventoryObject
for(var key in inventoryObject){
item = inventoryObject[key]; // here you will get each item from inventoryObject
//loop through fields in item
for (var f = 2, f > item.length, f++) {
field = item[f];
//check URL via item field's value
var code = checkURL(item[field].getvalue([field]));
//generate error based on code variable
createErrorRecord(code,item,field)
}
}
}
And yes welcome to Javascript
I am doing the below to get certain nodes from a treeview followed by getting text from those nodes, filtering text to remove unique and then appending custom image to the duplicate nodes.
For this I am having to loop 4 times. Is there is a simpler way of doing this? I am worried about it's performance for large amount of data.
//Append duplicate item nodes with custom icon
function addRemoveForDuplicateItems() {
var treeView = $('#MyTree').data('t-TreeView li.t-item');
var myNodes = $("span.my-node", treeView);
var myNames = [];
$(myNodes).each(function () {
myNames.push($(this).text());
});
var duplicateItems = getDuplicateItems(myNames);
$(myNodes).each(function () {
if (duplicateItems.indexOf($(this).text()) > -1) {
$(this).parent().append(("<span class='remove'></span>"));
}
});
}
//Get all duplicate items removing unique ones
//Input [1,2,3,3,2,2,4,5,6,7,7,7,7] output [2,3,3,2,2,7,7,7,7]
function getDuplicateItems(myNames) {
var duplicateItems = [], itemOccurance = {};
for (var i = 0; i < myNames.length; i++) {
var dept = myNames[i];
itemOccurance[dept] = itemOccurance[dept] >= 1 ? itemOccurance[dept] + 1 : 1;
}
for (var item in itemOccurance) {
if (itemOccurance[item] > 1)
duplicateItems.push(item);
}
return duplicateItems;
}
If I understand correctly, the whole point here is simply to mark duplicates, right? You ought to be able to do this in two simpler passes:
var seen = {};
var SEEN_ONCE = 1;
var SEEN_DUPE = 2;
// First pass, build object
myNodes.each(function () {
var name = $(this).text();
var seen = seen[name];
seen[name] = seen ? SEEN_DUPE : SEEN_ONCE;
});
// Second pass, append node
myNodes.each(function () {
var name = $(this).text();
if (seen[name] === SEEN_DUPE) {
$(this).parent().append("<span class='remove'></span>");
}
});
If you're actually concerned about performance, note that iterating over DOM elements is much more of a performance concern than iterating over an in-memory array. The $(myNodes).each(...) calls are likely significantly more expensive than iteration over a comparable array of the same length. You can gain some efficiencies from this, by running the second pass over an array and only accessing DOM nodes as necessary:
var names = [];
var seen = {};
var SEEN_ONCE = 1;
var SEEN_DUPE = 2;
// First pass, build object
myNodes.each(function () {
var name = $(this).text();
var seen = seen[name];
names.push(name);
seen[name] = seen ? SEEN_DUPE : SEEN_ONCE;
});
// Second pass, append node only for dupes
names.forEach(function(name, index) {
if (seen[name] === SEEN_DUPE) {
myNodes.eq(index).parent()
.append("<span class='remove'></span>");
}
});
The approach of this code is to go through the list, using the property name to indicate whether the value is in the array. After execution, itemOccurance will have a list of all the names, no duplicates.
var i, dept, itemOccurance = {};
for (i = 0; i < myNames.length; i++) {
dept = myNames[i];
if (typeof itemOccurance[dept] == undefined) {
itemOccurance[dept] = true;
}
}
If you must keep getDuplicateItems() as a separate, generic function, then the first loop (from myNodes to myNames) and last loop (iterate myNodes again to add the span) would be unavoidable. But I am curious. According to your code, duplicateItems can just be a set! This would help simplify the 2 loops inside getDuplicateItems(). #user2182349's answer just needs one modification: add a return, e.g. return Object.keys(itemOccurance).
If you're only concerned with ascertaining duplication and not particularly concerned about the exact number of occurrences then you could consider refactoring your getDuplicateItems() function like so:
function getDuplicateItems(myNames) {
var duplicateItems = [], clonedArray = myNames.concat(), i, dept;
for(i=0;i<clonedArray.length;i+=1){
dept = clonedArray[i];
if(clonedArray.indexOf(dept) !== clonedArray.lastIndexOf(dept)){
if(duplicateItems.indexOf(dept) === -1){
duplicateItems.push(dept);
}
/* Remove duplicate found by lastIndexOf, since we've already established that it's a duplicate */
clonedArray.splice(clonedArray.lastIndexOf(dept), 1);
}
}
return duplicateItems;
}
I have two Select lists, between which you can move selected options. You can also move options up and down in the right list.
When I move options back over to the left list, I would like them to retain their original position in the list order, even if the list is missing some original options. This is solely for the purpose of making the list more convenient for the user.
I am currently defining an array with the original Select list onload.
What would be the best way to implement this?
You can store the original order in an array, and when inserting back, determine what's the latest element in the array that precedes the one to be inserted AND matches what's currently in the select list. Then insert after that.
A better solution is to just store the old array whole and re-populate on every insertion with desired elements as follows (warning: code not tested)
function init(selectId) {
var s = document.getElementById(selectId);
select_defaults[selectId] = [];
select_on[selectId] = [];
for (var i = 0; i < s.options.length; i++) {
select_defaults[selectId][i] = s.options[i];
select_on[selectId][i] = 1;
var value = list.options[i].value;
select_map_values[selectId][value] = i if you wish to add/remove by value.
var id = list.options[i].id; // if ID is defined for all options
select_map_ids[selectId][id] = i if you wish to add/remove by id.
}
}
function switch(selectId, num, id, value, to_add) { // You can pass number, value or id
if (num == null) {
if (id != null) {
num = select_map_ids[selectId][id]; // check if empty?
} else {
num = select_map_values[selectId][value]; // check if empty?
}
}
var old = select_on[selectId][num];
var newOption = (to_add) : 1 : 0;
if (old != newOption) {
select_on[selectId][num] = newOption;
redraw(selectId);
}
}
function add(selectId, num, id, value) {
switch(selectId, num, id, value, 1);
}
function remove(selectId, num, id, value) {
switch(selectId, num, id, value, 0);
}
function redraw(selectId) {
var s = document.getElementById(selectId);
s.options.length = 0; // empty out
for (var i = 0; i < select_on[selectId].length; i++) {
// can use global "initial_length" stored in init() instead of select_on[selectId].length
if (select_on[selectId][i] == 1) {
s.options.push(select_defaults[selectId][i]);
}
}
}
I would assign ascending values to the items so that you can insert an item back in the right place. The assigned value stays with the item no matter which list it's in.
I have the following code that puts bold style some keywords in a whole google document:
function boldKeywords() {
// Words that will be put in bold:
var keywords = ["end", "proc", "fun"];
var document = DocumentApp.getActiveDocument();
var body = document.getBody();
var Style = {};
Style[DocumentApp.Attribute.BOLD] = true;
for (j in keywords) {
var found = body.findText(keywords[j]);
while(found != null) {
var foundText = found.getElement().asText();
var start = found.getStartOffset();
var end = found.getEndOffsetInclusive();
foundText.setAttributes(start, end, Style)
found = body.findText(keywords[j], found);
}
}
}
But I would like the code to put the keywords in bold only in the selected area of the document, for doing that, I tried using the function getSelection(), but I have the problem that this function returns a Range, but for applying findText I need a Body, somebody knows what could I do?
Modified Script
function boldKeywordsInSelection() {
const keywords = ["end", "proc", "fun"];
const document = DocumentApp.getActiveDocument();
const selection = document.getSelection();
// get a list of all the different range elements
const rangeElements = selection.getRangeElements();
const Style = {};
Style[DocumentApp.Attribute.BOLD] = true;
// forEach used here because for in was giving me trouble...
rangeElements.forEach(rangeElement => {
// Each range element has a corresponding element (e.g. paragraph)
const parentElement = rangeElement.getElement();
// fixing the limits of the bold operations depending on the selection
const startLimit = rangeElement.getStartOffset();
const endLimit = rangeElement.getEndOffsetInclusive();
for (j in keywords) {
let found = parentElement.findText(keywords[j]);
// wrapping in try catch to escape the for loop from within the while loop
try {
while (found != null) {
const foundText = found.getElement().asText();
const start = found.getStartOffset();
// Checking if the start of the word is after the start of the selection
if (start < startLimit) {
// If so, then skip to next word
found = parentElement.findText(keywords[j], found);
continue;
}
// Checking if the start of the word is after the end of the selection
// if so, go to next element
if (start > endLimit) throw "out of selection";
const end = found.getEndOffsetInclusive();
foundText.setAttributes(start, end, Style)
found = parentElement.findText(keywords[j], found);
}
} catch (e) {
Logger.log(e)
continue;
}
}
})
}
See the comments in the code for more details.
A getSelection produces a Range object, which contains within it various instances of RangeElement. Each RangeElement makes reference to a parent element, and the index positions within that parent. The parent is the element that the range element is a part of. For example:
This selection spans 3 elements. Therefore the selection has 3 range elements. You can only use the findText method on the whole element, not the range element.
This means that the flow of the script is generally the same, except that you need to go through each element and find the text within each element. Since this will return elements that are outside the selection, you need to keep track of the index positions of the selection and the found element and make sure the found element is within the selection.
References
Range
RangeElement
getSelection()