April 20, 2022

How to Check if String Contains Numbers and Special Characters in Javascript

By Krishnaa JavaScript Questions 0 Comments

In this tutorial, you will learn how to check if string contains numbers and special characters in javascript. A string can have both numbers as well as special characters. Almost all unreadable and punctuation characters fall into the category of special characters.

A number is nothing more than an arithmetic value that is used for representing the quantity and performing certain calculations. A number is formed by the combination of digits from 0 to 9. For a beginner, it can be a bit tricky to find if a string contains numbers and special characters.

There are numerous ways to check if a string contains numbers and sepcial characters. But for the sake of simplicity, we will use the regular expression and ternary operator (?) to accomplish our goal. The test() method of RegExpObject is used to perform a pattern search in a string and returns a Boolean value.

In the following example, we have one global variable that holds a string. Upon click of a button, we will check if the string contains numbers and special characters, 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 myString which holds a string as its value.
We have 2 regex patterns regexNumber and regexSpecial, one for numbers and another one for special characters.
In the event handler function, we are calling the test() method of regexNumber and regexSpecial. We are passing myString as a parameter. Both test() methods will return a boolean value.
We are also using logical AND operator (&&) to make sure the string contains numbers and special characters.
We are storing the final boolean value in the isMatch variable.
We are using the ternary operator (?) and checking whether isMatch is true or false. 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 myString = "Does Mr. James live in room number 3?";
let regexNumber = /\d/g;
let regexSpecial = /[`!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?~]/g;


btnCheck.addEventListener("click", () => {

  let isMatch = regexNumber.test(myString) && regexSpecial.test(myString);
  let result = isMatch ? "Yes" : "No";
  output.innerText = result;
  
});

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