Tags down


javascript array confusion between x = [x] && x.push(x) when var x;

By : Asmaa Ramadan
Date : October 16 2020, 08:10 AM
I wish did fix the issue. In case one, the line x.push(x); will throw an error if x is not defined - you can't access properties of an undefined object, of course.
In case two, x is not defined at the point the line x = [x]; is run, but you aren't trying to access any properties of x or anything like that - it's just an undefined value, which is OK. So, the expression [x] results in an array with one item, x (which is undefined), thus [undefined].
code :

Share : facebook icon twitter icon

How do I push a group of values to an array with Javascript push()?

By : Reese Montgomery
Date : March 29 2020, 07:55 AM
To fix this issue Can anybody spot the error here? Checkpoint 1 triggers but not checkpoint 2. Can't figure out what's wrong with my statement.
code :
items = {
    itemID: "B17",
    itemPrice: 17,
    itemQty: 1
items =[{
    itemID: "B17",
    itemPrice: 17,
    itemQty: 1

Javascript - Why returning array.push(x) from a function doens't push the element x into the array?

By : user3440872
Date : March 29 2020, 07:55 AM
may help you . If you look at the definition of the push method, it returns the length of the array after the push, not the array itself, that is why it is returning 1.

javascript array.push(array.push(x)) weird result

By : Daniela Ganea
Date : March 29 2020, 07:55 AM
I think the issue was by ths following , Array.prototype.push()

Javascript: Customizing an array push based on variable - allowing standard push call for some types

By : Belldozer85
Date : March 29 2020, 07:55 AM
this one helps. I am using the following technique to differentiate between copy-sourcing two different objects. The o2.copy does the deep copy while o3.copy does the shallow copy. , Use .call method for a function object to get default implementation.
code :
var A = [];

A.push = function (o) {
    if (typeof o === "object") {
        A[A.length] = {} 
        for (var key in o) {        
            A[A.length-1][key] = o[key];  
    } else {
        console.log("Non-object push");
        Array.prototype.push.call(this, o); //<--- How to call the default array push here

how to push an item into an array if it is inside a javascript object [state.lastValue.push is not a function]

By : Guillermo Gómez
Date : March 29 2020, 07:55 AM
this will help I'm updating some values as a javascript object inside my reducer in reactjs like below. , Update your state like
code :
state = {
  result:state.result + 400,
  lastval: [...state.lastval, 20]
Related Posts Related Posts :
  • How to handle state on array of checkboxes?
  • React Native - Redux ~ Props updating when not getting called
  • Fast way to add elements into an Uint8ClampedArray typed array
  • How to retrieve values from a checkbox group generated dinamically with jquery when page loads
  • Progress bar between two dates (fetch "var" from script), HTML
  • Why do Every time I start my function I get NaN
  • Angular routing change in url
  • Javascript - Change symbol on embedded tradingview script.text
  • How to select specific option?
  • Checking booleans from multiple arrays simultaneously, without multiple if statements
  • How to get a subarray?
  • Javascript JSON woes
  • Use Jquery animate to have a button move a box to the next corner
  • Why is this JavaScript not interpreted as a code block when semi-colon is used?
  • Reload another page when I click on button
  • Should functions that call a callback function be bound?
  • For loop print in single line separated by spaces - JS
  • Add Javascript Variable into asp-route-data
  • Two different POST requests are making use of the same variable
  • Convert JSOn object into a flat JSON Array
  • Manually adding to an HTML range input gives unexpected results
  • Refreshing component after making api call Reactjs
  • Google App Script : Finding The Last Blank Row
  • I cant for the life of me figure out whats wrong with this script
  • Order divs by ID in Javascript
  • set new element class property value
  • How to pass a java variable to a different jsp page containing javascript?
  • Locked it method in chai
  • React JS : history.push is not a function error and it isn't navigating to a different page onclick of swal
  • How can i set timeout for localstorage for Angular 2+?
  • Must use destructuring props assignment
  • Jest Compared values have no visual difference. when testing arrays
  • Uncaught Error: #90211 ExtensionName Error - Node.JS, Heroku, JavaScript App using FusionCharts
  • Is it possible in firebase auth to update user and custom claims at the same time node?
  • Filter out capitalized letters
  • Yet Another Google Firebase Error "Function returned undefined, expected Promise or value"
  • How do I address method in a Vue.js component from inside callback function?
  • What is the name of this feature in JavaScript?
  • Vue js using scope-slot and trying to use a property from within but having no visibility
  • Dynamic javascript table won't display iterations from array
  • How to start/end smoke.js animation by clicking a nav button?
  • Map array of strings as object properties
  • Appending new inputs with JS wipes previous ones
  • Chai Request With URL instead of JS File
  • React Jest Async Tests
  • Unordered list bullet not showing at an expected location
  • How to create an array from an object?
  • How to get prefix name from html tag
  • javascript - Simulate a click event (tap with finger) on a button in iOS
  • How to get the value of checkboxes in a kendo grid
  • Uncaught TypeError: Object(...) is not a function at eval (global-styles.js)
  • Generate divs on scroll bottom
  • App deployed to Cloud Foundry fails to start
  • Show label and percentage in Google pie chart
  • Warn user before leaving web page if changes haven't been saved
  • Objects are not valid as a React child getting error when adding div?
  • why is callback not working in nodejs with mysql?
  • D3 v4 date ticks never display last item
  • How to assign a variable which function takes as a parameter
  • Javascript how hidden div onclick of phrase
  • shadow
    Privacy Policy - Terms - Contact Us © voile276.org