Solve - data.map is not a function in JavaScript

In this tutorial, we are going to learn about how to solve the TypeError: data.map is not a function in JavaScript

When we use a Array.map() method on a value which is not an data type array we will get the following error in our console.

Example:

const data =  {
   name: "john",
   place: "italy"
};

obj.map(element => {
    console.log(element);
});

Output:

"TypeError: data.map is not a function

In the example above, we are getting the error because we using the map() method on a object.

To solve the error, we need to call the map() method on a data type array.

Here is an example:

const arr = [2, 3, 4];

arr.map(el=> el+2);

If you want to iterate over the object, use the Object.keys() method to get the object keys in a array format and loop through it using the map() method.

Here is an example:

const  user = {
   name: "john",
   place: "italy"
};

const keys = Object.keys(user);

keys.forEach(key=> {
    console.log(user[key]);
  }
);

Output:

"john"
"italy"

or we can use the Object.values() method which is similar to Object.keys() but it returns the values in array format.

const  user = {
   name: "john",
   place: "italy"
};

const values = Object.values(user);

values.forEach(value=> {
    console.log(value);
  }
);

Output:

"john"
"italy"