The indexOf() method starts at a specified index and searches from left to right (from the given start postion to the end of the array). By default the search starts at the first element and ends at the last.

var index = Data.findIndex(item => item.name == "John") Which is a simplified version of: var index = Data.findIndex(function(item){ return item.name == "John"}) From mozilla.org: The findIndex() method returns the index of the first element in the array that satisfies the provided testing function. Otherwise -1 is returned.

Dec 21, 2019 · shift can be used in places where you want to get the first element (index=0) of an array and chain with other array methods. example: const comps = [{}, {}, {}] const specComp = comps .map(fn1) .filter(fn2) .shift()

Dec 29, 2011 · How can I simply and directly find the index within an array of objects meeting some condition? For example, given this input: var hello = { hello: 'world', foo: 'bar'}; var qaz = { hello: 'stevie'...

Mar 13, 2025 · The indexOf() method of Array instances returns the first index at which a given element can be found in the array, or -1 if it is not present. Element to locate in the array. Zero-based index at which to start searching, converted to an integer.

Array.indexOf() returns -1 if the item is not found. If the item is present more than once, it returns the position of the first occurrence. Array.lastIndexOf() is the same as Array.indexOf(), but returns the position of the last occurrence of the specified element. Required. The item to search for. Optional. Where to start the search.

Mar 14, 2024 · In JavaScript, indexOf() methods provide the first index at which the given element exists, and -1 in case it is not present in the array. Syntax: indexOf(element)

Sep 27, 2024 · The JavaScript Array at() method takes an integer value (index) as a parameter and returns the element of that index. It allows positive and negative integers. For the negative integer, it counts back from the last element in the array.

Nov 18, 2024 · indexOf () returns the first index of a specified value in an array, or -1 if the value is not found. findIndex () is used for finding the index of an element based on complex conditions. It takes a callback function that can include any logic for locating an item within the array.

Sep 8, 2011 · The findIndex() method returns the index of the first element in the array that satisfies the provided testing function. Otherwise -1 is returned. var fooArray = [5, 10, 15, 20, 25]; console.log(fooArray.findIndex(num=> { return num > 5; })); // expected output: 1 Find an index by object property. To find an index by object property: