find index of array code example

Example 1: find index of object in array javascript

a = [
  {prop1:"abc",prop2:"qwe"},
  {prop1:"bnmb",prop2:"yutu"},
  {prop1:"zxvz",prop2:"qwrq"}];
    
index = a.findIndex(x => x.prop2 ==="yutu");

console.log(index);

Example 2: javascript get index of object with value in array

// Get index of object with specific value in array
const needle = 3;
const haystack = [{ id: 1 }, { id: 2 }, { id: 3 }];
const index = haystack.findIndex(item => item.id === needle);

Example 3: how to find the index of a value in an array in javascript

var list = ["apple","banana","orange"]

var index_of_apple = list.indexOf("apple") // 0

Example 4: findindex js

// 	findIndex(callback fn)  

//	.... return index (when condition meets)
//  .... return -1 (if condition not meets)

const array = [5, 12, 8, 130, 44];

/// it returns the index of number which satisfy the condition true
const index = array.findIndex((item)=> item>10);   //1

/// now we can check what element at that index...
console.log(array[index]); // array[1]

Example 5: js array get index

var fruits = ["Banana", "Orange", "Apple", "Mango"];
return fruits.indexOf("Apple"); // Returns 2

Example 6: get index of element in array javascript

var scores = [10, 20, 30, 10, 40, 20];
console.log(scores.indexOf(30)); // 2
console.log(scores.indexOf(50)); // -1