Give a phone number and the task is to format a phone number in such a way that it becomes easy to understand for humans.
There are two approaches to format the numbers which are discussed below:
- Using RegExp
- Using substr() Method
Approach 1: Using RegExp
- A RegExp is used to replace the original phone number with a human-readable phone number.
- The RegExp is searching for the 3 digits and saves it in a variable($1 for the first 3 digits, $2 for the second 3 digits, and so on.)
- In the end, It is just concatenating them with ‘-‘ among them.
Example: This example implements the above approach.
Javascript
const phoneNo = '4445556678' ; function formatNumber() { console.log( phoneNo .replace( /(\d{3})(\d{3})(\d{4})/, '$1-$2-$3' ) ); } formatNumber(); |
444-555-6678
Approach 2: Using substr() Method
- This example is using the substr() method to format a phone number in Human-Readable format.
- It is taking a substrings of length 3 and putting ‘-‘ among them. Remaining string elements using the same method.
Example: This example implements the above approach.
Javascript
const phoneNo = '4445556678' ; function formatNumber() { const formatNum = phoneNo.substr(0, 3) + '-' + phoneNo.substr(3, 3) + '-' + phoneNo.substr(6, 4); console.log(formatNum); } formatNumber(); |
444-555-6678