How to Trim First 4 Characters in Javascript
In this tutorial, you will learn how to trim first 4 characters in javascript. The first 4 characters in string can be letters, numbers, or special characters. For a newbie developer, it can be a bit tricky to trim first 4 characters of a string.
There are numerous ways to trim the first 4 characters of a string. We are going to use one of the easiest solutions which involve the usage of the substring()
method. A string consists of multiple characters and these characters in a string have a 0-based index. With the help of substring()
method, we can get the rest of the string after trimming the first 4 characters.
In the following example, we have one global variable that holds a string. Upon click of a button, we will trim the first 4 characters of the string and display the result on the screen. Please have a look over the code example and the steps given below.
HTML & CSS
- We have 3 elements in the HTML file (
div
,button
, andh1
). Thediv
element is just a wrapper for the rest of the elements. - The
innerText
for thebutton
element is“Get”
and for theh1
element, it is“Result”
. - We have done some basic styling using CSS and added the link to our
style.css
stylesheet inside thehead
element. - We have also included our javascript file
script.js
with ascript
tag at the bottom.
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <link rel="stylesheet" href="style.css"> <title>Document</title> </head> <body> <div class="container"> <button>Get</button> <h1>Result</h1> </div> <script src="script.js"></script> </body> </html>
.container { text-align: center; } button { margin-top: 10px; padding: 10px 20px; }
Javascript
- We have selected the
button
element andh1
element using thedocument.querySelector()
method and stored them inbtnGet
andoutput
variables respectively. - We have attached a
click
event listener to thebutton
element. - We have a global variable
myString
which holds a string as its value. - In the event handler function, we are calling the
substring()
method and passing 4 as a parameter which is the index of the fifth character“t”
. As a result, we will get a new string except for the first 4 characters"Jona"
. The new string will be stored in theresult
variable. - We are displaying the
result
in theh1
element using theinnerText
property.
let btnGet = document.querySelector("button"); let output = document.querySelector("h1"); let myString = "Jonathan is now in town"; btnGet.addEventListener("click", () => { let result = myString.substring(4); output.innerText = result; });