JavaScript: Check if String Contains Special Characters (Easy Guide).

In this blog post you’ll learn how to check for a string contains a special characters or not using JavaScript. Learn efficient ways to check for special characters in a string.

Way 1: Match Method With Regular Expression For Matching the Special Characters.

We’ll match for these special characters (!@#%^&*()_\|/?]/) in a given string. You can also use search() method.

JavaScript

	let string = "Hello & welcome to maketechstuff.com";
    console.log("string: ", string);

    if (string.match(/[!@#%^&*()_\|/?]/)) {
        console.log("Output: ", "No special characters are allowed in a string");
    } else {
        console.log("Output: ", "No problem");
    }
  

Output:

With special characters. (&).

In the above way I've added this special characters (!@#%^&*()_\|/?]/) check or match for it in a string. But you can also takes a different approach that allows only letters(a to z), dot(.), numbers and white spaces in a string.

Way 2: Match Method With Regular Expression For Matching the Characters Other than (a-Z),(0-9),(.) and Spaces.

We’ll show the error If any characters are present in a string other than the alphabet (small and capital), dot (.), numbers and white spaces.

JavaScript

	let string = "Hello & welcome to maketechstuff.com";
    console.log("string: ", string);

    if (string.match(/[^(.)\sA-Za-z0-9]/)) {
        console.log("Output: ", "Only letters (a to z), numbers, white spaces and dot(.) are allowed");
    } else {
        console.log("Output: ", "No problem");
    }

  

Output:

With special characters (&).

You also use search() method:

JavaScript

    let string = "hello welcome to maketechstuff.com";
    console.log("string: ", string);

    // Search method return -1 if no match found. And if match found, it returns the index value of the search value.
    let i = string.search(/[^\.\sa-zA-Z0-9]/);
    console.log("Search Method returns: ", i);

    if (i == -1) {
        console.log("Output: ", "No problem");
    } else {
        console.log("Output: ", "Only letters (a to z), numbers, white spaces and dot(.) are allowed");
    }

    // Output:
    // string:  hello welcome to maketechstuff.com
    // Search Method returns:  -1
    // Output:  No problem

So that's how you can check for special characters in a string using javascript. If you have any query or suggestion feel free to write in the comment section.

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