Zip Code Validation in JavaScript
We can easily track the address by validating the zip code because each city has a unique zip code. If we use the address for tracking, two cities may be in different places with the same name, so using a zip code is the correct way. Zipcode is very important if you are running any e-commerce website. Users may have typed the wrong zipcode so we need to validate them. So, in this article, we will see how to validation the zip code in javascript.
In the United States, zip codes are used to help identify geographic areas and to assist with mail delivery. Therefore, it is essential to validate zip codes entered by users on your website or application to ensure that they are accurate. These codes are a combination of five digits or nine digits that represent a specific geographic location within the country.
What is ZIP code validation?
ZIP code validation is the process of checking whether a user-entered ZIP code is valid or not. It involves verifying that the code has the correct format, length, and range. This validation is important because it ensures that the user enters a valid ZIP code that matches their location, which is critical for the successful delivery of mail and packages.
The length and format of the zip code varies from country to country. For example, In the US the zip code is five digits (12345) or five digits followed by four digits (12345-1234), Uk has a 6 to 8-character zip code (SW1W 0NY), etc.
How to validate the zip code?
Follow these methods to validate the zip code. We check whether there is a 5-digit or a 5-digit followed by 4 digits.
1. Regular expression:
It is one of the easiest and most common methods to validate the USA zip code in JavaScript
function zipValidate(zipCode) {
return /^\d{5}(-\d{4})?$/.test(zipCode);
}
console.log(zipValidate("12345")); // true
console.log(zipValidate("12345-6789")); // true
console.log(zipValidate("1234")); // false
console.log(zipValidate("12345-67")); // false
- In this above example code, we have created the function ‘zipValidate‘ with a parameter ‘zipCode‘.
- Inside the function, we use a regular expression to validate the ZIP code.
- Finally, a regular expression is tested against the ‘zipCode’ argument using the .test() method. This method returns true if the zipCode argument matches the regular expression, and false otherwise.
2. External library:
In this method, we use the zipcodes library to validate the ZIP code. This library provides a comprehensive database of ZIP codes and their associated information, including latitude and longitude, city, state, and county. Let’s see the example:
const zipcodes = require("zipcodes");
function zipValidate(zipCode) {
return zipcodes.lookup(zipCode) !== undefined;
}
console.log(zipValidate("12345")); // true
console.log(zipValidate("12345-6789")); // true
console.log(zipValidate("1234")); // false
console.log(zipValidate("12345-67")); // false
In this code:
- We import the ‘zipcodes’ library using the require() function.
- Then we create a function called ‘zipValidate’ with parameter ‘zipCode’.
- Inside the function, we call the lookup() method on the ‘zipcodes’ library, passing in the ‘zipCode’ argument. Then we check if the result of the ‘lookup()’ method is ‘undefined’ using the !== operator.
- Finally, we call the zipValidate function with passing zipcode. If the ZIP code is found in the database, the function returns true, indicating that the ZIP code is valid. If the ZIP code is not found in the database, the function returns false, indicating that the ZIP code is not valid.