check if javascript index is contained in a array code example

Example 1: javascript method to see if item exists in array

var fruits = ["Apple", "Banana", "Mango", "Orange", "Papaya"];
    
    // Check if a value exists in the fruits array
    if(fruits.indexOf("Mango") !== -1){
        alert("Value exists!")
    } else{
        alert("Value does not exists!")
    }

Example 2: if value in list javascript and return index

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

console.log(index);