Are you having a problem fixing the uncaught typeerror: e.indexof is not a function?

To quickly fix this error, you must first understand it.

In this article, we will discuss and fix the error mentioned above.

Let us start by knowing and understanding this error.

What is an uncaught typeerror: e.indexof is not a function?

The uncaught typeerror: e.indexof is not a function is an error message that occurs in JavaScript.

Incorrectly calling the “indexOf” function is the cause of this error.

What does this error indicate?

The error mentioned above indicates that the “e” variable is trying to call the indexOf function, but it does not have this function.

What is the indexOf() function?

In JavaScript, the indexOf() function is one of its built-in functions.

It is used to determine the index of a specific value within an array or string.

Back to the issue: it is possible that the “e” variable was planned to be an array or a string.

The problem might be that it was not initialized properly.

Here is a sample code that triggers this error:

let e = 42;
let i = e.indexOf("2");
console.log(i);

Error:

index.js:2
let i = e.indexOf("2");
          ^

TypeError: e.indexOf is not a function

Uncaught typeerror: e.indexof is not a function – SOLUTION

Time needed: 2 minutes

To fix the uncaught typeerror: e.indexof is not a function, inspect why the variable “e” is not working as it should.

Here is the guide you can follow to solve this error:

Verify that the “e” variable is properly initialized and is certainly an array or string.

To check the data type of the variable “e,” use the typeof operator.

To verify if the “e” variable is an array or a string, use conditional statements.

Ensure that the “e” variable has a value.

Do this before calling the indexOf function on it.

Same as step one, use a conditional statement if variable “e” is null or undefined.
Confirm that you are using the correct syntax.

Ensure that when calling the indexOf function on the “e” data type, you are using the correct syntax.

For example:

If “e” is an array, use “e.indexOf()”.
If “e” is a string, use “e.indexOg(“”)”.

Here is an example of code that fixes this error:

e = "String"

if (typeof e === "string" || Array.isArray(e)) {
  if (e !== null && e !== undefined) {
    let index = (typeof e === "string") ? e.indexOf("") : e.indexOf();
    console.log("Index: " + index);
  } else {
    console.log("Error: variable 'e' is null or undefined.");
  }
} else {
  console.log("Error: variable 'e' is not an array or a string.");
}

Output:

Index: 0

Conclusion

In conclusion, the uncaught typeerror: e.indexof is not a function is an error message that occurs in JavaScript.

You can fix this problem by inspecting why the variable “e” is not working as it should.

By following the guide above, you will surely solve this error quickly.

That is all for this tutorial, IT source coders!

We hope you have learned a lot from this. Have fun coding!

Thank you for reading! 😊