Search Results for: javascript array

This article will show you the ways to convert an object to an array in JavaScript – quickly and easily. There are many ways to convert objects to arrays, but these (should) be the most straightforward methods. Converting Object to Array in JavaScript – Values Only If you only need the values from the object, the Object.values() method will extract them into an array: var myObject = { colour: ‘blue’, number: 43, name: ‘Fred’, enabled: true }; var values = Object.values(myObject); console.log(values); The above will return an array with … Read more

The Object.entries() method in JavaScript can be used to convert an object to an array – but it doesn’t work recursively. So here’s a function to accomplish that. I can’t think of a reason why you’d want to do this, but it came up while putting together an article on using Object.entries() – so here it is! Recursive Function for Converting Objects to Arrays I’ll let the comments do the talking as to what’s going on. The gist of it is that (for whatever reason) you want to convert an … Read more

This quick tutorial will show you how to check whether an array is empty in the JavaScript programming language. What is an Array? An array is a type of variable that holds a collection of zero or more values. In JavaScript, arrays are ordered – each value in the array has a position (called the index) in the array, which is used to access it. Indexes start counting at 0, so the first value in an array is at index 0. Declaring an Array in JavaScript The quickest way to … Read more

This quick article will show you the right way to reset/clear/empty an array in the JavaScript programming language. The Right Way to Reset/Clear/Empty an Array – Set the length to 0 This is the best way to reset/clear/empty an array in JavaScript. It is unambiguous and will affect both the variable containing the array and any variables referencing the array. var myArray = [1, 2, 3, 4]; myArray.length = 0; Above, an array is declared and then emptied by setting the array’s length property to 0. The Wrong Way – Re-declare the … Read more

There are several ways to declare an array in JavaScript. This article will show you which is the best. What is an Array? An array is a type of variable that holds an ordered list of values. Each value has a position in the array, called the index. The index can be used to access each value in the array. Indexes are integer values, which start counting from 0 (zero) for the first item in the array. The Literal Constructor – Declaring an Array using Square Brackets (The Best … Read more

This tutorial will show you the correct ways to merge two or more arrays in JavaScript with the concat method – and provide a warning about how not to merge arrays. Merging/Joining Arrays in JavaScript with the concat()* Method The concat() method exists with one purpose – to merge arrays. concat() Method Syntax array.concat(ARRAYS) Note that: array is the first array of the arrays to be joined ARRAYS should be a comma-separated list of arrays to be added to the first array They will be joined in the order of appearance concat() returns a new array – … Read more

This article will show you a few ways, both easy and complex, to randomize/shuffle an array in JavaScript. The Quick and Dirty Way to Randomize an Array If you aren’t too concerned about the probabilities involved, this code is a quick way to randomize the contents of an array: // Function to return a shuffled copy of a given array function shuffle(array) { var shuffled = […array]; // Make a copy of the array to be shuffled so that the original is not altered by … Read more

This short article will show you how to reverse an array in the JavaScript programming language. What is an Array? An array is a type of variable that holds an ordered list of values. Each value has a position in the array, called the index – and can be accessed by using that index. As an array is ordered, the position matters. Values within arrays will be processed by loops and other data structures in order – so being able to reverse that order is beneficial. Reversing an … Read more

Here’s a short article that explains arrays and how to check if a JavaScript variable is an array using the Array.isArray() method. Want to check out whether an array contains a value? Find out how here. What is An Array? An array is a type of JavaScript variable that can hold other variables, or references to other variables, in a list at a certain position. Declaring an Array in JavaScript An array is declared in JavaScript the same way as any other variable – by assigning the value … Read more