javascript findindex

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

console.log(index);

const array1 = [5, 12, 8, 130, 44];
const findLargeNumber = element => element > 13;
console.log(array1.findIndex(findLargeNumber));
// expected output: 3

const array2 = [{id:1, dev:false}, {id:2, dev:false}, {id:3, dev:true}];
const WheresTheDev = obj => obj.dev === true;
console.log(array2.findIndex(WheresTheDev));
// expected output: 2

let myList = ['foo', 'bar', 'qux'];

myList.indexOf('bar');	// 1

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

// 	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]

var elementPos = array.map(function(x) {return x.id; }).indexOf(idYourAreLookingFor);
var objectFound = array[elementPos];

        
            
        
     let ranks = [1, 5, 7, 8, 10, 7];
let index = ranks.findIndex(rank => rank === 7);
console.log(index);

array.findIndex(call back function)

 //index of ............
 //first