Splice Is Not A Function Javascript

Splice Is Not A Function Javascript

5 min read Jun 20, 2024
Splice Is Not A Function Javascript

Splice is Not a Function: Understanding the Error and Finding Solutions

In JavaScript, encountering the "splice is not a function" error is a common issue, often caused by a misunderstanding of how the splice() method works or by a simple typo. This error message signifies that you are attempting to use the splice() method on a variable that is not an array, or you are calling it incorrectly.

Here's a breakdown of the problem and how to resolve it:

Understanding the Splice() Method

The splice() method is a powerful tool in JavaScript for manipulating arrays. It allows you to add or remove elements from an array at a specific index.


array.splice(start, deleteCount, item1, item2, ...);
  • start: The index at which to start changing the array.
  • deleteCount: The number of elements to remove from the array.
  • item1, item2, ...: Optional elements to add to the array at the specified index.


let colors = ["red", "green", "blue"];
colors.splice(1, 1, "yellow"); // Removes "green" and inserts "yellow" at index 1
console.log(colors); // Output: ["red", "yellow", "blue"]

Common Causes of the "Splice is Not a Function" Error

  1. Attempting to use splice() on a non-array variable: The most frequent mistake is trying to use splice() on a variable that is not an array. For instance, trying to apply splice() on a string or an object will result in this error.

  2. Typographical errors: A simple typo in the method name, such as "splic" instead of "splice", will cause the error.

Troubleshooting and Solutions

  1. Verify the variable type: Use the typeof operator to check the data type of the variable you're working with. If it's not an array, you'll need to convert it or use a different approach to manipulate its contents.

  2. Check for typos: Double-check the spelling of the splice() method. A single character error can cause the error to appear.

  3. Ensure the variable is declared correctly: Verify that the variable you're using is correctly declared as an array.

  4. Consider using other methods: If you're aiming to add or remove elements from an object, you might need to utilize other methods like Object.assign() or Object.keys().

Example of Fixing the Error

// Incorrect code
let myString = "Hello";
myString.splice(1, 1, "i"); // Throws "splice is not a function" error

// Corrected code
let myArray = ["H", "e", "l", "l", "o"];
myArray.splice(1, 1, "i");
console.log(myArray); // Output: ["H", "i", "l", "l", "o"]


The "splice is not a function" error is a common JavaScript hurdle. Understanding the purpose of the splice() method, verifying variable types, and correcting typos are crucial steps in resolving this error. Remember, always check your variable types and ensure you are using the correct method for manipulating data structures in JavaScript.