TypeError: object.push is not a function in JavaScript

TypeError: object.push is not a function in JavaScript #

The "object.push is not a function" error occurs because the push method is not implemented on objects. To solve the error, wrap the object in an array before calling the push method or add key-value pairs to the object using dot or bracket notation.

Here is an example of how the error occurs.

Copied!
const obj = {
  name: 'James',
  country: 'Chile',
};

// ⛔️ TypeError: object.push is not a function
obj.push({age: 30});

We called the Array.push method on an object, which caused the error.

To solve the error, we can wrap the object in an array and push a second object, or add key-value pairs to the object.

Copied!
const arr = [
  {
    id: 1,
    name: 'Alice',
  },
];

arr.push({id: 2, name: 'Bob'});

// 👇️ [{id: 1, name: 'Alice'}, {id: 2, name: 'Bob'}]
console.log(arr);

If you need to add key-value pairs to an object, use bracket or dot notation.

Copied!
const obj = {
  id: 1,
  name: 'Alice',
};

// 👇️ dot notation
obj.country = 'Chile';

// 👇️ bracket notation
obj['street address'] = 'Example street 123';

// 👇️ {id: 1, name: 'Alice', country: 'Chile', 'street address': ...}
console.log(obj);

You can also conditionally check if the value is an array before calling the push method to avoid getting errors.

Copied!
const arr = null;

if (Array.isArray(arr)) {
  arr.push({id: 2, name: 'Brad'});
}

We used the Array.isArray method to check if the value is an array before calling the push method.

If have an object and you want to push values to a specific property that stores an array, access the property and call the push() method on it.

Copied!
const obj = {
  numbers: [1, 2],
};

obj.numbers.push(3);

// 👇️ {numbers: [1, 2, 3]}
console.log(obj);

We accessed the numbers property, which stores an array and called the push() method to add an element to the array.

Conclusion #

The "object.push is not a function" error occurs because the push method is not implemented on objects. To solve the error, wrap the object in an array before calling the push method or add key-value pairs to the object using dot or bracket notation.