How to Trim a String to a Particular Length in Javascript
In this tutorial, you will learn how to trim a string to a particular length in javascript. The characters in a string can be or cannot be letters, numbers, or special characters. From a developer perspective, it can be a bit tricky to trim a string to a particular length.
There are numerous ways to trim a string to a particular length. A string consists of multiple characters and these characters in a string have a 0-based index. To trim a string to a particular length, we can make use of the slice()
method.
The slice()
method takes 2 parameters and they basically specify starting and ending index number of characters in a string for slicing purposes. The second parameter is optional and by default, it is considered to be the length of the string.
In the following example, we have one global variable that holds a string. Upon click of a button, we will trim a string to a particular length 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
slice()
method and passing 2 parameters, 0 which is the index of the first character, and 11 which is the index of the twelfth character. As a result, it will trim the string up to 11 characters and the final 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 = "I got some ninja skill, you know what I mean"; btnGet.addEventListener("click", () => { let result = myString.slice(0,11); output.innerText = result; });