Solve - push is not a function Error in JavaScript

Solve - push is not a function Error #

The "push is not a function" error occurs when the push() method is called on a value that is not an array. To solve the error, convert the value to an array before calling the method, or make sure to only call the push() method on valid arrays.

Here is an example of how the error occurs.

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const arr = {name: 'Tom'};

// ⛔️ Uncaught TypeError: arr.push is not a function
arr.push({name: 'James'});

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

In this situation, we should place the object in an array, so we are able to push new objects into the array.

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const arr = [{name: 'Tom'}];

arr.push({name: 'James'});

// 👇️ [{name: 'Tom'}, {name: 'James'}]
console.log(arr);

If you got the error when working with a NodeList or other array-like object, convert the array-like object to an array before calling the push() method.

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const set = new Set(['a', 'b']);

const arr = Array.from(set);
console.log(arr); // 👉️ ['a', 'b']

arr.push('c');

console.log(arr); // 👉️ ['a', 'b', 'c']

We used the Array.from() method to convert a Set object to an array, so we can call the push() method on the array.

Here is an example that checks if the value is an array before calling the push() method.

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const arr = null;

if (Array.isArray(arr)) {
  arr.push('example');
}

If you're working with an object, there's a good chance that you need to access a specific property that stores an array, so you can call the push() method.

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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 on the array.