April 18, 2022

How to Check if a String Contains Text from an Array of Substrings in Javascript

By Krishnaa JavaScript Questions 0 Comments

In this tutorial, you will learn how to check if a string contains text from an array of substrings in javascript. An array is just a collection of items and these items can be of any data type. A string consists of multiple characters and these characters can be letters, numbers, or special characters. For a beginner, it can be a bit tricky to find if a string contains text from an array of substrings.

There are numerous ways to check if a string contains text from an array of substrings. But for the sake of simplicity, we will use include() method, some() method and ternary operator (?) to accomplish our goal.

The includes() method is used to perform a case-sensitive search to detect whether a string contains another string or not and returns a Boolean value. The some() method executes a certain function for each element in an array. The some() method returns true if the returned value of the function is true for at least one element.

In the following example, we have 2 global variables, an array and a string. Upon click of a button, we will check if the string contains text from an array of substrings 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 2 global variables myString and users. We need to check if myString contains a text from users array.
In the event handler function, we are calling some() method on users and looping through each element in the array. We are using includes() to check if myString contains a text from users array.
After the completion, some() method will return either true or false. We are storing that in the found variable. If it is true, that means myString does contain a text from users array.
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 users = ["Steve", "Marks", "Karl", "Peter", "James"];
let myString = "Steve is a very rich guy";

btnCheck.addEventListener("click", () => {
  let found = users.some((item) => myString.includes(item));
  let result = found ? "Yes" : "No";
  output.innerText = result;
});

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