How to Check if Array Contains Only Empty Strings in Javascript

In this tutorial, you will learn how to check if array contains only empty strings in javascript. An array is just a collection of items and these items can be of any data type.. A string that has a length of 0 is considered to be an empty string. For a beginner, it can be a bit tricky to find if an array contains only empty strings.

There are numerous ways to check if an array contains only empty strings. But for the sake of simplicity, we will use trim() method, every() method, length property, and ternary operator (?) to accomplish our goal.

The trim() method returns a new string after removing spaces at the beginning and the end of a given string. The every() method executes a certain function for each element in an array. The every() method returns true if the returned value of the function is true for all elements. The length property returns the length of a string.

In the following example, we have an array and upon click of a button, we will check if the array contains only empty strings 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 “Check” 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>Check</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 btnCheck and output variables respectively.
  • We have attached a click event listener to the button element.
  • We have a global variable words which holds an array that contains only empty strings.
  • In the event handler function, we are calling every() method on words and looping through each element in the array. We are using trim() method to get rid of whitespace and getting the length of the string using length property. We are checking if the length of the string is equal to 0.
  • After the completion, every() method will return either true or false. We are storing that in the isEmpty variable. If it is true, that means words array does contain only empty strings.
  • Depending upon the result of the check, we will assign “Yes” or “No” to the result variable.
  • We are displaying the result in the h1 element using the innerText property.
let btnCheck = document.querySelector("button");
let output = document.querySelector("h1");

let words = ["", "", ""];

btnCheck.addEventListener("click", () => {
  let isEmpty = words.every((word) => word.trim().length == 0);
  let result = isEmpty ? "Yes" : "No";
  output.innerText = result;
});