How to check the object property in javascript - javascript

I have an array like below
var colorArray = ["#a", "#b", "#c", "#d", "#e"];
From this I will generate a map like this
function initilizeColorMap(){
for(var i = 0 ;i <colorArray.length ;i++){
colorTrackingMap[i] = {value: colorArray [i],state:"unused"};
}
}
Hopw i can iterate through the map when i need a color (next color from the map ) by checking the state in javascript..?


You can have a method that will return the next color. Check out this jsfiddle : http://jsfiddle.net/QYWDb/
var colorArray = ["#a", "#b", "#c", "#d", "#e"];
var colorTrackingMap = [];
var currentIndex = -1;
for(var i = 0 ;i <colorArray.length ;i++){
colorTrackingMap[i] = {value: colorArray [i],state:"unused"};
}
function getNextColor() {
if (currentIndex > colorTrackingMap.length)
currentIndex = 0;
else
currentIndex++;
while ( colorTrackingMap[currentIndex] !== undefined &&
colorTrackingMap[currentIndex].state !== "unused" ) {
currentIndex++;
}
if ( colorTrackingMap[currentIndex] )
return colorTrackingMap[currentIndex].value;
else
return "No color available";
}


If you need color according to given index you don't have to iterate, use such code:
var currentIndex = 0;
function Next() {
var tracking = colorTrackingMap[currentIndex];
alert("color: " + tracking.value + ", state: " + tracking.state);
currentIndex++;
if (currentIndex >= colorTrackingMap.length)
currentIndex = 0;
}
Live test case.
If you mean searching the array for item with specific value, just use ordinary loop:
function Find() {
var color = document.getElementById("color").value;
var state = "";
for (var i = 0; i < colorTrackingMap.length; i++) {
if (colorTrackingMap[i].value.toLowerCase() === color) {
state = colorTrackingMap[i].state;
break;
}
}
if (state.length == 0) {
alert("color isn't mapped");
} else {
alert("state: " + state);
}
}
You can also pass the color as function argument, this is just for sake of example.
Updated test case.


You could use something like this:
var ColourMap = function (arr) {
var _map = [],
out = [],
i,
len;
// Set up the colour map straight away
for (i = 0, len = arr.length; i < len; i++) {
_map.push({
value: arr[i],
state: "unused"
});
}
return {
get_next: function () {
var i,
len,
next;
for (i = 0, len = _map.length; i < len; i++) {
if (_map[i].state === "unused") {
next = _map[i];
break;
}
}
return next;
}
}
};
And then use something like:
var m = new ColourMap(["#a", "#b", "#c", "#d", "#e"]);
m.get_next(); // get the next available element
Here's a working example.

Related

Trying to make a function that returns selected CSS properties but is pretty laggy

I was trying to make a function that gives you the selected CSS properties of an element those you want. But it's pretty laggy if used in console as of it needs to get and match all CSS properties.
function styleOf(elementUseSelectors, propertiesToCheck, tellInConsole) {
var element = elementUseSelectors;
var Arguments = propertiesToCheck;
var calculatedProperties = [];
var matchedProperties = [];
if (tellInConsole !== undefined && tellInConsole == true) {
console.warn("Running styleOf() Please Don't Do Other Calculations This Function Disables Console.")
}
for (var i = 0; i < Object.keys(getComputedStyle(element)).length; i++) {
var value = getComputedStyle(element).getPropertyValue(Object.entries(getComputedStyle(element))[i][0].replace(/([A-Z])/g, ' $1').trim().replaceAll(" ", "-").toLowerCase());
if (value !== "") {
calculatedProperties.push(Object.entries(getComputedStyle(element))[i][0].replace(/([A-Z])/g, ' $1').trim().replaceAll(" ", "-").toLowerCase() + ": " + value);
}
}
for (var i = 0; i < calculatedProperties.length; i++) {
for (var a = 0; a < Arguments.length; a++) {
if (calculatedProperties[i].includes(Arguments[a])) {
window.splitted = calculatedProperties[i].split("");
window.joinThis = [];
for (var k = 0; k < splitted.indexOf(":"); k++) {
joinThis.push(splitted[k]);
};
if (joinThis.join("") == Arguments[a]) {
matchedProperties.push(calculatedProperties[i]);
}
}
}
}
if (tellInConsole !== undefined && tellInConsole == true) {
console.warn("StyleOf() Calculations Completed You Can Now Use Console.")
}
return matchedProperties
}

The TreeWalker object is designed to quickly parse DOM nodes in a document. If you expand on the example given above in the MDN Web Docs you can output the computed CSS properties for a given node.
The first property of the method is the node you want to traverse – in this case it's document.body:
var treeWalker = document.createTreeWalker(
document.body,
NodeFilter.SHOW_ELEMENT,
{ acceptNode: function(node) { return NodeFilter.FILTER_ACCEPT; } },
false
);
var nodeList = [];
var currentNode = treeWalker.currentNode;
while(currentNode) {
nodeList.push(currentNode);
const style = getComputedStyle(currentNode)
console.log(style)
currentNode = treeWalker.nextNode();
console.log("moving to next node...");
}

Welp #kaiido answered the question.
function styleOf(element, properties) {
const computed = getComputedStyle(element);
return properties.map( key => key + ": " + computed[ key ] )};
var style = styleOf(document.getElementsByTagName("body")[0], ["height", "width", "background-color", "font-size", "color", "font-family"]);
console.log(style);

Having Trouble figuring out the highest value through a for in loop

I am having trouble figuring out a way to loop the object in the objectMap to give me the Highest value of the fruits it gathered.My question is, how do I get loop to get the highest value using a for in loop. I have attached my code below.And where i have stopped,by the for in loop
var fruitString = 'Banana,Banana,Pear,Orange,Apple,Melon,Grape,Apple,Banana,Grape,Melon,Grape,Melon,Apple,Grape,Banana,Orange,Melon,Orange,Banana,Banana,Orange,Pear,Grape,Orange,Orange,Apple,Apple,Banana'
var fruitList = fruitString.split(',')
var fruitMap = {};
function soldfruits(){
for (var i = 0; i < fruitList.length; i++) {
var currentFruit = fruitList[i]
if (fruitMap[currentFruit] === undefined) {// cehck if fruit is not available
fruitMap[currentFruit]= 0;
}
fruitMap[currentFruit] = fruitMap[currentFruit] +1
}
console.log(fruitMap);
}
soldfruits(fruitMap); // calling function for check.
for (var fruits in fruitMap) {
if ( ) {
}
}

Try this:
var fruitString = 'Banana,Banana,Pear,Orange,Apple,Melon,Grape,Apple,Banana,Grape,Melon,Grape,Melon,Apple,Grape,Banana,Orange,Melon,Orange,Banana,Banana,Orange,Pear,Grape,Orange,Orange,Apple,Apple,Banana'
var fruitList = fruitString.split(',')
var fruitMap = {};
function soldfruits(){
for (var i = 0; i < fruitList.length; i++) {
var currentFruit = fruitList[i]
if (fruitMap[currentFruit] === undefined) {
fruitMap[currentFruit]= 0;
}
fruitMap[currentFruit] = fruitMap[currentFruit] +1
}
console.log(fruitMap);
return fruitMap
}
var fmap = soldfruits(fruitMap);
var high = 0
var high_name = ''
for(var x in fmap)
{
if(fmap[x] > high)
{
high = fmap[x]
high_name = x
}
}
console.log(high + ' ' + high_name)

This code will return the highest number of fruit sold and also the names of those fruit.
var mostSold = 0;
var mostFruits = [];
for (var fruits in fruitMap) {
if (fruitMap[fruits] > mostSold) {
// store the number of fruit sold
mostSold = fruitMap[fruits];
// initialise the list with the fruit name
mostFruits = [fruits];
}
else if (fruitMap[fruits] == mostSold) {
// add the fruit name to the list
mostFruits.push(fruits);
}
}
console.log( mostSold + ' : ' + mostFruits );

Like this:
var highest = {fruit:"", num:0}
for (var fruit in fruitMap) {
var num = fruitMap[fruit];
if (num > highest.num) { // if the current number of fruits is greater than the saved
highest.fruit=fruit; // save the fruit
highest.num=num; // save the number
}
}
console.log(highest);
Alternatively sort the array using object sort and pop the last
var fruitString = 'Banana,Banana,Pear,Orange,Apple,Melon,Grape,Apple,Banana,Grape,Melon,Grape,Melon,Apple,Grape,Banana,Orange,Melon,Orange,Banana,Banana,Orange,Pear,Grape,Orange,Orange,Apple,Apple,Banana'
var fruitList = fruitString.split(',')
var fruitMap = {};
function soldfruits() {
for (var i = 0; i < fruitList.length; i++) {
var currentFruit = fruitList[i]
if (fruitMap[currentFruit] === undefined) {
fruitMap[currentFruit] = 0;
}
fruitMap[currentFruit] = fruitMap[currentFruit] + 1
}
console.log(fruitMap);
}
soldfruits(fruitMap);
var highest = {fruit:"", num:0}
for (var fruit in fruitMap) {
var num = fruitMap[fruit];
if (num > highest.num) {
highest.fruit=fruit;
highest.num=num;
}
}
console.log(highest);

You could loop with Array#forEach and check, if fruitList has a value of the propery fruit. If not take zero otherwise the value of the propery and add one. Then assign to the property.
var fruitString = 'Banana,Banana,Pear,Orange,Apple,Melon,Grape,Apple,Banana,Grape,Melon,Grape,Melon,Apple,Grape,Banana,Orange,Melon,Orange,Banana,Banana,Orange,Pear,Grape,Orange,Orange,Apple,Apple,Banana',
fruitList = fruitString.split(','),
fruitMap = {},
highest = 0;
fruitList.forEach(function (fruit) {
fruitMap[fruit] = (fruitMap[fruit] || 0) + 1;
if (fruitMap[fruit] > highest) {
highest = fruitMap[fruit];
}
});
console.log(fruitMap);
console.log(highest);
.as-console-wrapper { max-height: 100% !important; top: 0; }

Push to an array in a nested loop is repeating the last value

I am trying to push elements to an array in a nested loop, but only the last item is getting repeated in the final array, where am I going wrong, very new to javascript asynchronous concept.Below is the function in which I push the items to an array.
$scope.showBeList = function(feed) {
if (feed[srcServ.KEY_CONTENT_TEXT]) {
var content = JSON.parse(feed[srcServ.KEY_CONTENT_TEXT])
if (content) {
$scope.beList = {};
for (var key in content) {
var decorationVal;
//reading value from a lokijs collection
var decoration = dataServ[srcServ.CONST_COLLECTION_DECORATION].find({
'name': key
});
if (decoration && decoration.length) {
decorationVal = decoration[0];
if (decorationVal != null) {
var tempObj = JSON.parse(decorationVal.value);
if (tempObj) {
var header = tempObj[key][key + '_HEADER'];
if (header) {
var counter = content[key].length;
var tempItems = [];
for (var j = 0; j < content[key].length; j++) {
(function(j) {
var obj = {};
obj[srcServ.KEY_MAIN_HEADER] = tempObj[key][srcServ.KEY_DESC];
obj[srcServ.KEY_SUB_HEADER] = header[srcServ.KEY_DESC];
obj.id = j;
var itemVal = content[key][j][key + '_HEADER'];
var details = [];
var notes = [];
for (var item in itemVal) {
var val = null;
var found = false;
for (var i = 0; i < header.field.length; i++) {
if (header.field[i].name == item) {
val = header.field[i];
found = true;
break;
}
}
if (found && val != null) {
val[srcServ.KEY_DESC_VALUE] = itemVal[item];
details.push(val);
}
}
obj.details = details;
counter--;
if (counter == 0) {
$scope.showMoreDetails = true;
$scope.beList.beItems = tempItems;
console.log(JSON.stringify($scope.beList));
}
tempItems.push(obj)
})(j);
// $scope.beList.beItems.push(obj);
}
}
}
}
}
}
}
}
}

Deleting from an array doesn't work

So, I'm trying to delete from an array if it's element value isn't equal to a value that I specified:
Code: http://pastebin.com/hUc3mVLv
$scope.enablePVR = function()
{
for (i = 0; i < $scope.new_epg.length; i++) {
start_time = convert_time($scope.new_epg[i].start);
$scope.new_epg[i].title = $scope.new_epg[i].title.replace(/<(?:.|\n)*?>/gm, '');
$scope.new_epg[i].description = "";
$scope.new_epg[i].time = start_time;
}
archiveEPG = [];
for(var i=0; i<archiveEPG.length; i++) {
var e = document.getElementById("dateSelect");
if($scope.new_epg[i].start.split(" ")[0] == e[e.selectedIndex].value) {
archiveEPG[archiveEPG.length+1] = $scope.new_epg[i];
}
}
document.getElementById("dateSelect").remove(0);
$scope.get_epg(null, true, archiveEPG);
}

.remove(0) isn't valid you can add this function to make it valid tho :
Array.prototype.remove = function(index) {
return this.splice(index, 1); // The second parameter is the number of elements to remove.
}

JavaScript continue label scope

Map.prototype.updateMap = function (vehicles) {
nextVehicle:
for (var i = 0; i < vehicles.length; i++) {
for (var j = 0; j < this.oldVehicles.length; j++) {
var vehicle = vehicles[i];
var oldVehicle = this.oldVehicles[j];
if (vehicle.registration == oldVehicle.registration) {
oldVehicle.getPosition(function(latLng) {
if (vehicle.latitude != oldVehicle.lat) {
var newPos = new plugin.google.maps.LatLng(vehicle.latitude, vehicle.longitude);
oldVehicle.setPosition(newPos);
}
continue nextVehicle;
});
}
}
}
};
The code above does not work. I have a feeling this is to do with scope, I can't reach the nextVehicle label from inside the oldVehicle.getPosition method. How can I get around this?

Separate the matching logic from the update logic.
Map.prototype.updateMap = function (vehicles) {
// Only need to look up array lengths once
var vehiclesLength = vehicles.length,
oldVehiclesLength = this.oldVehicles.length;
for (var i = 0; i < vehiclesLength; i++) {
var vehicle = vehicles[i];
var oldVehicle = null;
// Find oldVehicle
for (var j = 0; j < oldVehiclesLength; j++) {
if (vehicle.registration == oldVehicle[j].registration) {
oldVehicle = oldVehicles[j];
break;
}
}
// Check for update if found
if (oldVehicle){
// Create closure for async callbacks
(function(oldV, lat,lng){
oldV.getPosition(function(latLng) {
if (lat != oldV.lat) {
var newPos = new plugin.google.maps.LatLng(lat,lng);
oldV.setPosition(newPos);
}
});
})(oldVehicle, vehicle.latitude, vehicle.longitude);
}
}
};

Just move the continue nextVehicle; line from inside the callback to immediately following the call to oldVehicle.getPosition(...):
Map.prototype.updateMap = function (vehicles) {
nextVehicle:
for (var i = 0; i < vehicles.length; i++) {
for (var j = 0; j < this.oldVehicles.length; j++) {
var vehicle = vehicles[i];
var oldVehicle = this.oldVehicles[j];
if (vehicle.registration == oldVehicle.registration) {
oldVehicle.getPosition(function(latLng) {
if (vehicle.latitude != oldVehicle.lat) {
var newPos = new plugin.google.maps.LatLng(vehicle.latitude, vehicle.longitude);
oldVehicle.setPosition(newPos);
}
});
continue nextVehicle;
}
}
}
};
This assumes the call to getPosition is a synchronous operation.
Edit:
Now if getPosition is asynchronous, you will need to use an asynchronous loop:
Something along this line might do the trick:
Map.prototype.updateMap = function (vehicles) {
var i = 0, j = -1, self = this;
var updatePosition = function() {
j++;
if (j == self.oldVehicles.length) {
j = 0;
i++;
}
if (i === vehicles.length) {
return; // We're done
}
var vehicle = vehicles[i];
var oldVehicle = self.oldVehicles[j];
if (vehicle.registration !== oldVehicle.registration) {
updatePosition();
}
else {
oldVehicle.getPosition(function(latLng) {
if (vehicle.latitude != oldVehicle.lat) {
var newPos = new plugin.google.maps.LatLng(vehicle.latitude, vehicle.longitude);
oldVehicle.setPosition(newPos);
updatePosition();
}
});
}
};
updatePosition();
};

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