JavaScript Searching an Array


Example

The recommended way (Since ES5) is to use Array.prototype.find:

let people = [
  { name: "bob" },
  { name: "john" }
];

let bob = people.find(person => person.name === "bob");

// Or, more verbose
let bob = people.find(function(person) {
  return person.name === "bob";
});

In any version of JavaScript, a standard for loop can be used as well:

for (var i = 0; i < people.length; i++) {
  if (people[i].name === "bob") {
    break; // we found bob
  }
}

FindIndex

The findIndex() method returns an index in the array, if an element in the array satisfies the provided testing function. Otherwise -1 is returned.

array = [
  { value: 1 },
  { value: 2 },
  { value: 3 },
  { value: 4 },
  { value: 5 }
];
var index = array.findIndex(item => item.value === 3); // 2
var index = array.findIndex(item => item.value === 12); // -1