Develop Reference

Get a value of a HashTable

I was making a HashTable to have as an example and have it saved for any problem, but I ran into a problem trying to implement a method that returns true or false in case the value belongs to the HashTable, since it is inside a arrays of objects as comment in the code.
I have tried for loops, .map and for of, but it always fails, if someone could help me.
function HashTable () {
this.buckets = [];
this.numbuckets = 35;
}
HashTable.prototype.hash = function (key) {
let suma = 0;
for (let i = 0; i < key.length; i++) {
suma = suma + key.charCodeAt(i);
}
return suma % this.numbuckets;
}
HashTable.prototype.set = function (key, value) {
if (typeof key !== "string") {
throw new TypeError ("Keys must be strings")
} else {
var index = this.hash(key);
if(this.buckets[index] === undefined) {
this.buckets[index] = {};
}
this.buckets[index][key] = value;
}
}
HashTable.prototype.get = function (key) {
var index = this.hash(key);
return this.buckets[index][key];
}
HashTable.prototype.hasKey = function (key) {
var index = this.hash(key);
return this.buckets[index].hasOwnProperty(key)
}
HashTable.prototype.remove = function (key) {
var index = this.hash(key);
if (this.buckets[index].hasOwnProperty(key)) {
delete this.buckets[index]
return true;
}
return false;
}
HashTable.prototype.hasValue = function (value) {
let result = this.buckets;
result = result.flat(Infinity);
return result // [{Name: Toni}, {Mame: Tino}, {Answer: Jhon}]
}

You can use Object.values() to get the values of all the propertyies in the bucket.
function HashTable() {
this.buckets = [];
this.numbuckets = 35;
}
HashTable.prototype.hash = function(key) {
let suma = 0;
for (let i = 0; i < key.length; i++) {
suma = suma + key.charCodeAt(i);
}
return suma % this.numbuckets;
}
HashTable.prototype.set = function(key, value) {
if (typeof key !== "string") {
throw new TypeError("Keys must be strings")
} else {
var index = this.hash(key);
if (this.buckets[index] === undefined) {
this.buckets[index] = {};
}
this.buckets[index][key] = value;
}
}
HashTable.prototype.get = function(key) {
var index = this.hash(key);
return this.buckets[index][key];
}
HashTable.prototype.hasKey = function(key) {
var index = this.hash(key);
return this.buckets[index].hasOwnProperty(key)
}
HashTable.prototype.remove = function(key) {
var index = this.hash(key);
if (this.buckets[index].hasOwnProperty(key)) {
delete this.buckets[index]
return true;
}
return false;
}
HashTable.prototype.hasValue = function(value) {
return this.buckets.some(bucket => Object.values(bucket).includes(value));
}
let h = new HashTable;
h.set("Abc", 1);
h.set("Def", 2);
console.log(h.hasValue(1));
console.log(h.hasValue(3));

XML To JSON Conversion with attributes

I am trying to convert the XML to JSON.Here am facing challenge my xml have #attributes name as "value" in all tag. while convert into xml to JSON i am using the below code.
var xml = "<Message><id value="123"></id><type value="Test"></type></Message>"
var json = XMLtoJSON(xml, ["type", "space", "xmlns", "html"]);
var result = JSON.stringify(json)
function XMLtoJSON(xml, ignored) {
var r, children = xml.*, attributes = xml.#*, length = children.length();
if(length == 0) {
r = xml.toString();
} else if(length == 1) {
var text = xml.text().toString();
if(text) {
r = text;
}
}
if(r == undefined) {
r = {};
for each (var child in children) {
var name = child.localName();
var json = XMLtoJSON(child, ignored);
var value = r[name];
if(value) {
if(value.length) {
value.push(json);
} else {
r[name] = [value, json]
}
} else {
r[name] = json;
}
}
}
if(attributes.length()) {
var a = {}, c = 0;
for each (var attribute in attributes) {
var name = attribute.localName();
if(ignored && ignored.indexOf(name) == -1) {
a["_" + name] = attribute.toString();
c ++;
}
}
if(c) {
if(r) a._ = r;
return a;
}
}
return r;
}
Input XML :
<Message><id value="123"></id><type value="Test"></type></Message>
Actual Output:
{"id":{"_value":"123"},"type":{"_value":"Test"}}
Expected Output:
{"id":"123","type":"Test"}
Guide me where am missing the part to get the expected output.
Regards,
nkn1189

do you think if you do this way will work for you?
put your actual output from that parser to this function:
function convertToExpectedOutput(obj){
var result = {}
for (var i in obj){
if (i == "_value")
return obj[i];
else
result[i] = convertToExpectedOutput(obj[i])
}
return result;
}
convertToExpectedOutput(actualOutput)
So, for your array, hange the convertToExpectedOutput to this way and it will give the expected result:
function convertToExpectedOutput(obj){
var result = {}
for (var i in obj){
if (i == "_value")
return obj[i];
else
if (Array.isArray(obj[i])){
result[i] = [];
arr = obj[i]
for (var j in arr)
result[i].push(convertToExpectedOutput(arr[j]))
}
else
result[i] = convertToExpectedOutput(obj[i])
}
return result;
}

Readability of Javascript Array

I have a JSON OBJECT similar to following
{
"kay1":"value1",
"key2":"value2",
"key3":{
"key31":"value31",
"key32":"value32",
"key33":"value33"
}
}
I want to replace that with JSON ARRAY as follows
[
"value1",
"value2",
[
"value31",
"value32",
"value33"
]
]
My motivation to change the the JSON OBJECT to JSON ARRAY is it takes less amount of network traffic, getting the value from ARRAY is efficient than OBJECT, etc.
One problem I face is the readability of the ARRAY is very less than OBJECT.
Is there any way to improve the readability?

Here you go, I have written a function which will convert all instances of object to array and give you the result you are expecting.
var objActual = {
"key1":"value1",
"key2":"value2",
"key3":{
"key31":"value31",
"key32":"value32",
"key33": {
"key331" : "value331",
"key332" : "value332"
}
}
};
ObjectUtil = {
isObject : function(variable) {
if(Object.prototype.toString.call(variable) === '[object Object]') {
return true;
}
return false;
},
convertToArray : function(obj) {
var objkeys = Object.keys(obj);
var arr = [];
objkeys.forEach(function(key) {
var objectToPush;
if(ObjectUtil.isObject(obj[key])) {
objectToPush = ObjectUtil.convertToArray(obj[key]);
} else {
objectToPush = obj[key];
}
arr.push(objectToPush);
});
return arr;
}
};
var result = ObjectUtil.convertToArray(objActual);
console.log(result);

In my opinion, it should be:
{
"kay1":"value1",
"key2":"value2",
"key3":["value31", "value32", "value33"]
}

Using the init method is time critical. So use a scheme or assign static JSON to Storage.keys and assign your bulk data array to store.data. You can use store.get("key3.key31") after that. http://jsfiddle.net/2o411k00/
if (!Array.prototype.map)
{
Array.prototype.map = function(fun /*, thisp*/)
{
var len = this.length;
if (typeof fun != "function")
throw new TypeError();
var res = new Array(len);
var thisp = arguments[1];
for (var i = 0; i < len; i++)
{
if (i in this)
res[i] = fun.call(thisp, this[i], i, this);
}
return res;
};
}
var data = {
"kay1":"value1",
"key2":"value2",
"key3":{
"key31":"value31",
"key32":"value32",
"key33":"value33"
}
}
var Storage = function(data){
this.rawData = data;
return this;
}
Storage.prototype.init = function(){
var self = this;
var index = 0;
var mp = function(dat, rootKey){
var res = Object.keys(dat).map(function(key, i) {
var v = dat[key];
if (typeof(v) === 'object'){
mp(v, key);
} else {
self.data.push(v);
var nspace = rootKey.split(".").concat([key]).join(".");
self.keys[nspace] = index++;
}
});
}
mp(this.rawData, "");
}
Storage.prototype.get = function(key){
return this.data[this.keys[key]];
};
Storage.prototype.data = [];
Storage.prototype.keys = {};
var store = new Storage(data);
console.log(data);
store.init();
console.log("keys", store.keys);
console.log("data", store.data);
console.log("kay1=", store.get(".kay1"));
console.log("key2=", store.get(".key2"));
console.log("key3.key31=", store.get("key3.key31"));
console.log("key3.key32=",store.get("key3.key32"));
console.log("key3.key33=", store.get("key3.key33"));

how to reindex object start from 0

I have an object output from below code how to set the index start from 0 in js?
Object
3: Object
id: 34
type: 0
var obj = {};
var edited = false;
for (var i = 0; i < $(".list").length; i++) {
var data_id = parseInt($(".list").eq(i).attr('data-id'));
var data_type = parseInt($(".list").eq(i).attr('data-type'));
if ((data_type != 0)) {
edited = true;
} else {
edited = false;
}
if (edited == true) {
obj[i] = {};
obj[i]['id'] = data_id;
obj[i]['type'] = data_type;
}
}
console.log(obj);

Needs more jQuery ?
var arr = $(".list").filter(function() {
return $(this).data('type') != 0;
}).map(function() {
return { id : $(this).data('id'), type : $(this).data('type') };
}).get();
FIDDLE

Actually if you want to start in 0, use another variable and not "i" (which I think is 3 when you use it as index).
var obj = {};
var edited = false;
var obj_idx = 0;
for (var i = 0; i < $(".list").length; i++) {
var data_id = parseInt($(".list").eq(i).attr('data-id'));
var data_type = parseInt($(".list").eq(i).attr('data-type'));
if ((data_type != 0)) {
edited = true;
} else {
edited = false;
}
if (edited == true) {
obj[obj_idx] = {};
obj[obj_idx]['id'] = data_id;
obj[obj_idx]['type'] = data_type;
obj_idx += 1;
}
}
console.log(obj);
I think this time obj will be something like:
Object
0: Object
id: 34
type: 0

you could fake object as array by Array.prototype.push.call, in that way you could also gain the side effect: obj.length. it's kinda ninja and elegant :]
var obj = {};
var edited = false;
for (var i = 0; i < $(".list").length; i++) {
var data_id = parseInt($(".list").eq(i).attr('data-id'));
var data_type = parseInt($(".list").eq(i).attr('data-type'));
if ((data_type != 0)) {
edited = true;
} else {
edited = false;
}
if (edited == true) {
Array.prototype.push.call(obj, {id: data_id, type: data_type});
}
}

I am going to give a very simple and readable example. Say you've got an object with the following structure:
Object
0: Object
key: 'some-key'
value: 'some-value'
1: Object
...
Then you might want to delete an entry from it and reindex the whole thing, this is how I do it:
// obj is Object from above
const reIndexed = Object.entries(obj).map((element, index) => {
if (parseInt(element[0] != index) {
element[0] = index.toString();
}
return element;
});

Dynamically building array, appending values

i have a bunch of options in this select, each with values like:
context|cow
context|test
thing|1
thing|5
thing|27
context|beans
while looping through the options, I want to build an array that checks to see if keys exist, and if they don't they make the key then append the value. then the next loop through, if the key exists, add the next value, comma separated.
the ideal output would be:
arr['context'] = 'cow,test,beans';
arr['thing'] = '1,5,27';
here's what i have so far, but this isn't a good strategy to build the values..
function sift(select) {
vals = [];
$.each(select.options, function() {
var valArr = this.value.split('|');
var key = valArr[0];
var val = valArr[1];
if (typeof vals[key] === 'undefined') {
vals[key] = [];
}
vals[key].push(val);
});
console.log(vals);
}

Existing code works by changing
vals=[];
To
vals={};
http://jsfiddle.net/BrxuM/

function sift(select) {
var vals = {};//notice I made an object, not an array, this is to create an associative array
$.each(select.options, function() {
var valArr = this.value.split('|');
if (typeof vals[valArr[0]] === 'undefined') {
vals[valArr[0]] = '';
} else {
vals[valArr[0]] += ',';
}
vals[valArr[0]] += valArr[1];
});
}
Here is a demo: http://jsfiddle.net/jasper/xtfm2/1/

How about an extensible, reusable, encapsulated solution:
function MyOptions()
{
var _optionNames = [];
var _optionValues = [];
function _add(name, value)
{
var nameIndex = _optionNames.indexOf(name);
if (nameIndex < 0)
{
_optionNames.push(name);
var newValues = [];
newValues.push(value);
_optionValues.push(newValues);
}
else
{
var values = _optionValues[nameIndex];
values.push(value);
_optionValues[nameIndex] = values;
}
};
function _values(name)
{
var nameIndex = _optionNames.indexOf(name);
if (nameIndex < 0)
{
return [];
}
else
{
return _optionValues[nameIndex];
}
};
var public =
{
add: _add,
values: _values
};
return public;
}
usage:
var myOptions = MyOptions();
myOptions.add("context", "cow");
myOptions.add("context","test");
myOptions.add("thing","1");
myOptions.add("thing","5");
myOptions.add("thing","27");
myOptions.add("context","beans");
console.log(myOptions.values("context").join(","));
console.log(myOptions.values("thing").join(","));
working example: http://jsfiddle.net/Zjamy/

I guess this works, but if someone could optimize it, I'd love to see.
function updateSiftUrl(select) { var
vals = {};
$.each(select.options, function() {
var valArr = this.value.split('|');
var key = valArr[0];
var val = valArr[1];
if (typeof vals[key] === 'undefined') {
vals[key] = val;
return;
}
vals[key] = vals[key] +','+ val;
});
console.log(vals);
}

Would something like this work for you?
$("select#yourselect").change(function(){
var optionArray =
$(":selected", $(this)).map(function(){
return $(this).val();
}).get().join(", ");
});
If you've selected 3 options, optionArray should contain something like option1, option2, option3.

Well, you don't want vals[key] to be an array - you want it to be a string. so try doing
if (typeof vals[key] === 'undefined') {
vals[key] = ';
}
vals[key] = vals[key] + ',' + val;