I have no idea why I'm getting this error, I'm using trie.js from github and trying to use the add function, but it says that trie.add isn't a function.
var longestWord = function(words) {
console.log('test');
let trie = new Trie();
trie.add("test");
console.log(trie);
};
longestWord('testing');
function Trie() {
this.head = {
key : ''
, children: {}
}
}
Trie.prototype.add = function(key) {
var curNode = this.head
, newNode = null
, curChar = key.slice(0,1);
key = key.slice(1);
while(typeof curNode.children[curChar] !== "undefined"
&& curChar.length > 0){
curNode = curNode.children[curChar];
curChar = key.slice(0,1);
key = key.slice(1);
}
while(curChar.length > 0) {
newNode = {
key : curChar
, value : key.length === 0 ? null : undefined
, children : {}
};
curNode.children[curChar] = newNode;
curNode = newNode;
curChar = key.slice(0,1);
key = key.slice(1);
}
};
Trie.prototype.search = function(key) {
var curNode = this.head
, curChar = key.slice(0,1)
, d = 0;
key = key.slice(1);
while(typeof curNode.children[curChar] !== "undefined" && curChar.length > 0){
curNode = curNode.children[curChar];
curChar = key.slice(0,1);
key = key.slice(1);
d += 1;
}
if (curNode.value === null && key.length === 0) {
return d;
} else {
return -1;
}
}
Trie.prototype.remove = function(key) {
var d = this.search(key);
if (d > -1){
removeH(this.head, key, d);
}
}
function removeH(node, key, depth) {
if (depth === 0 && Object.keys(node.children).length === 0){
return true;
}
var curChar = key.slice(0,1);
if (removeH(node.children[curChar], key.slice(1), depth-1)) {
delete node.children[curChar];
if (Object.keys(node.children).length === 0) {
return true;
} else {
return false;
}
} else {
return false;
}
}
All the code I added myself is before function Trie(). The rest of it is from this github repo: https://gist.github.com/alexandervasyuk/b12c3d2c306539decb2a#file-trie-js
You are calling new Trie before adding prototypes to it.
This is working version:
https://jsbin.com/jokekuw/3/edit?js,output
var longestWord = function(words) {
console.log('test');
let trie = new Trie();
trie.add("test");
};
function Trie() {
this.head = {
key : ''
, children: {}
}
}
Your code should be moved to after the Trie declaration and prototype initialization.
The Trie constructor function (Trie) declaration will be hoisted to the top of the code block. Your code can therefore be successful in instantiating a new object with it. However, at the time you try to use the object, the Trie prototype has not yet been initialized. The prototype initialization statements are just ordinary statements, so they will be executed after your call to longestWord().
Thus if you move everything of yours that is currently before function Trie ... to the end of the overall code block, it should work (barring other errors).
Related
Here is the code I have gathered and worked on so far. I can't seem to get my remove function to work correctly. It keeps saying "Cannot read properties of undefined (reading 'value') when I try to execute it on the last two lines. Any tips or help would be appreciated, thank you!
function LinkedList() {
this.head = null;
this.tail = null;
this.length = 0;
}
function Node(value) {
this.value = value;
this.next = null;
}
// adds a node to the specified index
// if index is specified, accepts parameter (value, index)
// if no index is specified then add element to the end of list
LinkedList.prototype.add = function(...value) {
if (!this.head) {
this.head = this.tail = new Node(...value);
this.length++;
return;
}
while (value.length) {
let curr = value.pop();
this.tail.next = new Node(curr);
this.tail = this.tail.next;
this.length++;
}
}
// retrieves the node at the specified index
LinkedList.prototype.get = function(index) {
if (index >= this.length) {
return -1;
}
if (index === 0) {
return this.head;
}
let previousNode = null;
let currentNode = this.head;
for (let i = 0; i < index; i++) {
if (!currentNode.next) {
break;
}
previousNode = currentNode;
currentNode = currentNode.next;
}
previousNode.next = currentNode.next;
this.length--;
return currentNode;
}
// retrieves and removes the node at the specified index
// if no index is specified, removes the last node (tail)
LinkedList.prototype.remove = function(index) {
if (this.length === 0) {
return undefined;
}
if (this.head.value === index) {
this.removeFromHead();
return this;
}
let previousNode = this.head;
let thisNode = previousNode.next;
while (thisNode) {
if (thisNode.value === index) {
break;
}
previousNode = thisNode;
thisNode = thisNode.next;
}
if (thisNode === null) {
return undefined;
}
previousNode.next = thisNode.next;
this.length--;
return this;
}
LinkedList.prototype.removeFromHead = function() {
if (this.length === 0) {
return undefined;
}
const value = this.head.value;
this.head = this.head.next;
this.length--;
return value;
}
let linkedList = new LinkedList()
linkedList.add(0);
linkedList.add(1, 0);
linkedList
console.log(linkedList.remove().value) //should return 1
console.log(linkedList.remove().value) //should return 2
I'm not all cuteseed up
Here is the code:
function BinarySearchNode(key) {
let node = {};
node.key = key;
node.lft = null;
node.rgt = null;
node.log = () => {
console.log(node.key);
}
node.get_node_with_parent = (key) => {
let parent = null;
while (this) {
if (key == this.key) {
return [this, parent];
}
if (key < this.key) {
[this, parent] = [this.lft, this];
} else {
[this, parent] = [this.rgt, this];
}
}
return [null, parent];
}
return node;
}
My Firefox is 44.0 and it throws a SyntaxError for these lines:
if (key < this.key) {
[this, parent] = [this.lft, this];
} else {
I tried to understand what exactly is wrong here by reading this blogpost and the MDN. Unfortuntely, I am still missing it :(
this is not a variable, but a keyword and cannot be assigned to. Use a variable instead:
node.get_node_with_parent = function(key) {
let parent = null;
let cur = this; // if you use an arrow function, you'll need `node` instead of `this`
while (cur) {
if (key == cur.key) {
return [cur, parent];
}
if (key < cur.key) {
[cur, parent] = [cur.lft, cur];
} else {
[cur, parent] = [cur.rgt, cur];
}
}
return [null, parent];
}
I'd like to create a recursive function to parse json-like data as below. When key is xtype, a new class will be created. In particular, when xtype = gridpanel/treepanel, all the properties have to be its constructor argument, otherwise, properties will be added after class has been created.
My recursive function as below, I got an error 'too much recursion' at line 21 in ext-all.js.
Please take a look, how am I able to solve this problem?
codes in main program:
me.recursiveParser(null, data.json);
Ext.apply(me.root, me.parent);
me.desktopCfg = me.root;
recursiveParser function:
recursiveParser: function(nodeName, jsonData) {
var properties = {};
var isSpecial = false;
var isLeaf = true;
var parent, child, special;
//Base factor
for (var key in jsonData) {
var value = jsonData[key];
//To collect all the properties that is only initialized with '#'.
if (key.toString().indexOf("#") === 0) {
key = key.replace("#", "");
if(typeof(value) === "string"){
properties[key] = "'"+value+"'";
}else{
//Later, should have to deal with the empty value or array with no keys and only elements.
properties[key] = value;
}
if(key === "xtype"){
//To initialize the root
if(nodeName === null){
this.root = this.createNewObject(value, null);
}
if(value === "gridpanel" || value === "treepanel"){
isSpecial = true;
special = value;
}else{
child = this.createNewObject(value, null);
}
}
}else {
isLeaf = false;
}
}
if(isSpecial){
child = this.createNewObject(special, properties);
}
//To add the subnode and its properties to its parent object.
if (nodeName !== null && typeof(nodeName) === "string") {
if(child === null){
Ext.apply(parent, properties);
}else{
Ext.apply(parent, child);
}
}
if(isLeaf){
return;
}
for (var key in jsonData) {
var value = jsonData[key];
if (key.toString().indexOf("#") === 0) {
continue;
}else{
if(value === "[object Object]"){
for(var index in value){
this.recursiveParser(key, value[index]);
}
}else{
this.recursiveParser(key, value);
}
Ext.apply(this.root, parent);
}
}
}
createNewObject function:
createNewObject: function(objType, properties){
if(objType){
switch (objType){
case "gridpanel":
return new MyProg.base.GridPanel(properties);
break;
case "treepanel":
return new MyProg.base.TreePanel(properties);
break;
case "tabpanel":
return new MyProg.base.TabPanel();
break;
case "tab":
return new MyProg.base.Tabs();
break;
case "formpanel":
return new MyProg.base.Accordion();
break;
case "fieldset":
return new MyProg.base.FieldSet();
break;
case "textfield":
return new MyProg.base.Fields();
break;
case "panel":
return new MyProg.base.Accordion();
break;
default:
return new MyProg.base.Accordion();
};
};
}
data.json:
var data = {
"json": {
"#title": "BusinessIntelligence",
"#xtype": "tab",
"#layout": "accordion",
"items": [
{
"#title": "SalesReport",
"#ctitle": "SalesReport",
"#layout": "column",
"items": [
{}
]
},
{
"#title": "ContentPlayingReport",
"#ctitle": "ContentPlayingReport",
"#layout": "column",
"items": [
{}
]
},
{
"#title": "BusinessIntelligence",
"#ctitle": "BusinessIntelligence",
"#layout": "column",
"items": [
{}
]
}
]
}
}
I modified the recursion part, it looks more elegant now. All the xtype works just fine, except gridpanel, I've check DOM, everything is in there, but still got error message:
TypeError: c is undefined
...+g.extraBaseCls);delete g.autoScroll;if(!g.hasView){if(c.buffered&&!c.remoteSort...
ext-all.js (line 21, col 1184416)
I suspect it's an ExtJS bug. I'll try to find another way out.
recursion program:
recursiveParser: function (jsonData) {
var me = this;
var properties = {};
for ( var key in jsonData ){
var value = jsonData[key];
var items = (value.constructor === Array) ? [] : {};
if (value instanceof Object) {
if (isNaN(key)){
if (items.constructor === Array) {
for (var node in value){
items.push(me.recursiveParser(value[node]));
}
properties[key] = items;
} else {
properties[key] = me.recursiveParser(value);
}
} else {
return me.recursiveParser(value);
}
} else {
if (key.toString().indexOf('#') === 0){
key = key.replace('#', '');
properties[key] = value;
}
}
}
return properties;
}
I can across this very useful angular filter. I wanted to alter it so it removes any items that aren't explicitly filtered for. Right now if any key has a property which isn't recognized it ignores they key entirely. Essentially I want items filtered out if a key's property isn't present. For instance if $scope.searchName doesn't match it should be removed by the filter.
I got the filter here.
https://stackoverflow.com/a/21169596/2292822
<div ng-repeat="item in filtered = (items | filterMultiple:queryBy)>
Here is the relevant scope variables and filter
$scope.queryBy = {name:$scope.searchName, y1:$scope.selectedYear,y2:$scope.selectedYear,y3:$scope.selectedYear,y4:$scope.selectedYear};
myApp.filter('filterMultiple',['$filter',function ($filter) {return function (items, keyObj) {
var filterObj = {
data:items,
filteredData:[],
applyFilter : function(obj,key){
var fData = [];
if (this.filteredData.length == 0)
this.filteredData = this.data;
if (obj){
var fObj = {};
if (!angular.isArray(obj)){
fObj[key] = obj;
fData = fData.concat($filter('filter')(this.filteredData,fObj));
} else if (angular.isArray(obj)){
if (obj.length > 0){
for (var i=0;i<obj.length;i++){
if (angular.isDefined(obj[i])){
fObj[key] = obj[i];
fData = fData.concat($filter('filter')(this.filteredData,fObj));
}
}
}
}
if (fData.length > 0){
this.filteredData = fData;
}
}
}
};
if (keyObj){
angular.forEach(keyObj,function(obj,key){
filterObj.applyFilter(obj,key);
});
}
return filterObj.filteredData;}}]);
I made a few changes to the code, it works for me now, hopefully it works for you too!
myApp.filter('filterMultiple',['$filter',function ($filter) {return function (items, keyObj) {
var x = false;
var filterObj = {
data:items,
filteredData:[],
applyFilter : function(obj,key){
var fData = [];
if (this.filteredData.length == 0 && x == false)
this.filteredData = this.data;
if (obj){
var fObj = {};
if (!angular.isArray(obj)){
fObj[key] = obj;
fData = fData.concat($filter('filter')(this.filteredData,fObj));
} else if (angular.isArray(obj)){
if (obj.length > 0){
for (var i=0;i<obj.length;i++){
if (angular.isDefined(obj[i])){
fObj[key] = obj[i];
fData = fData.concat($filter('filter')(this.filteredData,fObj));
}
}
}
}
if (fData.length > 0){
this.filteredData = fData;
}
if (fData.length == 0) {
if(obj!= "" && obj!= undefined)
{
this.filteredData = fData;
x = true;
}
}
}
}
};
if (keyObj){
angular.forEach(keyObj,function(obj,key){
filterObj.applyFilter(obj,key);
});
}
return filterObj.filteredData;}}]);
I'm working on a calculator that takes an expression such as (5+4) and evaluates it by passing the buttons pressed to an array, and then building a parse tree from the data in the array.
What's interesting/strange, is that my code won't push the value of the right parenthesis to the array. Here is my code, could someone help me out?
The console.log activeButton shows that is the value of the button being pressed, but even when I placed calcArray.push() outside the if statements it would not push ) to an array.
$(document).ready(function(){
var calcArray = new Array();
$("input").click(function(){
var activeButton = this.value;
console.log(activeButton);
if(!isNaN(activeButton))
{
calcArray.push(parseInt(activeButton));
console.log(calcArray);
}
else if(activeButton === "=")
{
evaluate(buildTree(calcArray));
calcArray = [];
}
else
{
calcArray.push(activeButton);
}
});
});
The BuildTree code:
function BinaryTree(root) {
this.root = root;
this.activeNode = root;
}
function Node(element){
this.element = element;
this.parent;
this.rightChild;
this.leftChild;
this.setLeft = function(node){
this.leftChild = node;
node.parent = this;
};
this.setRight = function(node){
this.rightChild = node;
node.parent = this;
};
}
//methods
var buildTree = function(array)
{
var tree = new BinaryTree(new Node(null));
for(var i = 0; i < array.length; i++)
{
var newNode = new Node(array[i]);
if(array[i] == "(")
{
newNode.element = null;
tree.activeNode.setLeft(newNode);
tree.activeNode = newNode;
}
else if(array[i] == "+" || array[i] == "-" || array[i] == "/" || array[i] == "*")
{
tree.activeNode.element = newNode.element;
tree.activeNode.setRight(new Node(null));
tree.activeNode = tree.activeNode.rightChild;
}
else if(array[i] == ")")
{
if(tree.activeNode.parent == null)
{
;
}
else
{
tree.activeNode = tree.activeNode.parent;
tree.root = tree.activeNode;
}
}
else
{
tree.activeNode.element = newNode.element;
tree.activeNode = tree.activeNode.parent;
}
}
return tree.activeNode;
}
var evaluate = function(node){
var newNode1, newNode2;
newNode1 = new Node(null);
newNode1.parent = node;
newNode2 = new Node(null);
newNode2.parent = node;
if(node.leftChild == null && node.rightChild == null)
return node.element;
else{
newNode1.element = evaluate(node.leftChild);
newNode2.element = evaluate(node.rightChild);
if(newNode1.parent.element == "+")
{
return Number(newNode1.element) + Number(newNode2.element);
}
if(newNode1.parent.element == "-")
{
return newNode1.element - newNode2.element;
}
if(newNode1.parent.element == "*")
{
return newNode1.element * newNode2.element;
}
else
{
return newNode1.element / newNode2.element;
}
}
};
I just tried this out using your code and it worked fine passing the value as a string:
function pushButton (value) {
var activeButton = value;
console.log(activeButton);
if(!isNaN(activeButton))
{
calcArray.push(parseInt(activeButton));
console.log(calcArray);
}
else if(activeButton === "=")
{
evaluate(buildTree(calcArray));
calcArray = [];
}
else
{
calcArray.push(activeButton);
}
};
You aren't ever printing out the array in the last case (which is where the right paren would go), so are you sure it's not on the array and you just aren't seeing the visual feedback?
If so, we need to see more of your code. Try and setup a jsfiddle.