... “Invert” a JavaScript object hash whose values are arrays to produce a new object hash with keys as the elements of those original value vectors. In other words, filter() gives you a new array containing just the elements you need. I have a nested Object where some keys like app1 are nested inside another object. We are required to write a JavaScript function that takes one such array as the first argument and a search query string as the second argument. Return true to keep the element, false otherwise. How to calculate the number of days between two dates in javascript? filter() has a single parameter, a callback method. JavaScript : find an object in array based on object's property (and learn about the "find" function) Published on March 20, 2017 March 20, 2017 • 331 Likes • 50 Comments Report this post It returns a Boolean value. The filter() method creates a new array with all elements that pass the test implemented by the provided function. If the callback function returns true, it … Updating a value in a nested array of objects. Here is a basic example of what I want. Using the Array filter Method to Remove Items By Value. It looks like your function is doing unnecessary filtering that will not filter it right. However, like most programming languages, JavaScript lets you create arrays inside arrays, known as nested arrays. Array reduce method is very powerful and it can be used to safely access nested objects. var newArray = array.filter(function(item) { return condition; }); The item argument is a reference to the current element in the array as filter() checks it against the condition. How to set the default value for an HTML