You’ve now learned how to use Array Find to grab any particular element you want in your array, in any way you want to find it.Īrray Find is a nice and compact way that we can declaratively search through an array and get a copy of the first matched element. Inside the loop, we then find the item and assign it to the found variable, and break the loop - giving us a nice imperative “find” solution. Why? Because by default, it’s undefined - you can explicitly assign it if you like, though. length i ++ ) įirst we declare let found and do not assign a value. I publish a few articles and tutorials each week, please consider entering your email here if you’d like to be added to my once-weekly email list.// `undefined` by default let found for ( let i = 0 i < items. Therefor, if the remainder does not equal zero, we have an odd number: function isOdd(i) arr.findIndex(isOdd) // 4Īs expected, the index (4) of the odd number (9) is returned! Want more advanced JavaScript?Ĭheck out: A Beginners Guide to Advanced JavaScript An even number will always have a remainder of 0. To do this, we’ll check the remainder of the number divided by 2.

Next, we need a function to determine if a number is odd.

What if we have an Array with all even numbers and one odd number? We can find the odd number with Array.find(). If it does, the value of that entry is returned. In the above example we are testing each entry in the array to see if it equals ‘b’.

We’ll use an array with three entries: let arr = arr.find(k => k='b') // 'b' find() does not mutate or change the original Array.If nothing passes, undefined is returned.find() method executes a callback function once for each element in the array until it finds a value that returns true.The Array.find() method returns the value of the first element in an array that passes a given test.

Javascript find element in array