January 29, 2022

How to Get First Letter of String in Javascript

By Krishnaa JavaScript Questions 0 Comments

In this tutorial, you will learn how to get first letter of a string in javascript. The formation of string involves letters, numbers as well as special characters. This means at the very first position, we may have a letter, number, or special character.

There are numerous ways to get the first letter of a string. A string consists of multiple characters and to extract only letters from it, we can make use of the regular expression. To further get only the first letter, we can use the slice() method.

The slice() method takes 2 parameters and they basically specify starting and ending index number of items in an array for slicing purposes. The second parameter is optional and by default, it is considered to be the length of the array.

In the following example, we have one global variable that holds a string. Upon click of a button, we will get the first letter 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, and h1). The div element is just a wrapper for the rest of the elements.
The innerText for the button element is “Get” and for the h1 element, it is “Result”.
We have done some basic styling using CSS and added the link to our style.css stylesheet inside the head element.
We have also included our javascript file script.js with a script 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 and h1 element using the document.querySelector() method and stored them in btnGet and output variables respectively.
We have attached a click event listener to the button element.
We have a global variable myString which holds a string as its value.
In the event handler function, we are calling the match() method and passing /[a-zA-Z]/g as a regex pattern. As a result, we will get an array of letters or an empty array if there are no letters in the string. The array will be stored in the letters variable.
Further, we will validate the length of the array and then call the slice() method. We will pass this method 2 parameters; 0 which is the index of the first letter and 1 which is the index of the second letter. As a result, we will get the only first letter and that will be stored in the result variable.
We are displaying the result in the h1 element using the innerText property.

let btnGet = document.querySelector("button");
let output = document.querySelector("h1");

let myString = "Hello world";

btnGet.addEventListener("click", () => {
  let letters = myString.match(/[a-zA-Z]/g) || [];
  let result = letters.length > 0 ? letters.slice(0,1) : '';
  output.innerText = result;
});

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