We can add objects into an array using different JavaScript methods, and below are some examples.
Using push()
The push() function adds an object at the end of the array.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>How to Add an Object Inside an Array in JavaScript?</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
</head>
<body>
<script>
var cities = [
{ id: 1, name: "Patna", state: "Bihar" },
{ id: 2, name: "Gaya", state: "Bihar" },
{ id: 3, name: "Bangalore", state: "Karnataka" },
{ id: 4, name: "Bhopal", state: "Madhya Pradesh" },
{ id: 5, name: "Agra", state: "Utter Pradesh" },
{ id: 6, name: "Kanpur", state: "Utter Pradesh" },
{ id: 7, name: "Kannur", state: "Kerala" },
];
cities.push({ id: 8, name: "Hyderabad", state: "Telangana" });
console.log(cities);
</script>
</body>
</html>
Output:

Using unshift()
The unshift() function adds an object at the start of the array.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>How to Add an Object Inside an Array in JavaScript?</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
</head>
<body>
<script>
var cities = [
{ id: 1, name: "Patna", state: "Bihar" },
{ id: 2, name: "Gaya", state: "Bihar" },
{ id: 3, name: "Bangalore", state: "Karnataka" },
{ id: 4, name: "Bhopal", state: "Madhya Pradesh" },
{ id: 5, name: "Agra", state: "Utter Pradesh" },
{ id: 6, name: "Kanpur", state: "Utter Pradesh" },
{ id: 7, name: "Kannur", state: "Kerala" },
];
cities.unshift({ id: 0, name: "Hyderabad", state: "Telangana" });
console.log(cities);
</script>
</body>
</html>
Output:

Using splice()
The splice() function allows inserting an object at any index.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>How to Add an Object Inside an Array in JavaScript?</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
</head>
<body>
<script>
var cities = [
{ id: 1, name: "Patna", state: "Bihar" },
{ id: 3, name: "Bangalore", state: "Karnataka" },
{ id: 4, name: "Bhopal", state: "Madhya Pradesh" },
{ id: 5, name: "Agra", state: "Utter Pradesh" },
{ id: 6, name: "Kanpur", state: "Utter Pradesh" },
{ id: 7, name: "Kannur", state: "Kerala" },
];
cities.splice(1, 0, { id: 2, name: "Hyderabad", state: "Telangana" });
console.log(cities);
</script>
</body>
</html>
Output:

Description of Functions
push(): Adds an object to the end of the arrayunshift(): Adds an object to the beginning of the arraysplice(): Adds an object at a specific index without removing others