How to search a vertical tab character with JavaScript RegExp ?

In this article, we will see how to search a vertical tab character with JavaScript RegExp. A vertical tab character (VT) is a control character used to cause a printer or display device to move its output up by one line. It has an ASCII code of 11 or 0x0B.
In JavaScript regular expressions, the vertical tab character can be searched using its escape sequence `\v`. It can be useful when you want to search for the presence of vertical tab characters in a string.

Syntax: The syntax for searching a vertical tab character using a regular expression in JavaScript is:

/[\v]/g

This regular expression uses the character class `[\v]` to match any vertical tab character in the input string. The `g` flag is used to perform a global search, which means that all matches will be found, not just the first one.

Approaches: To search for a vertical tab character with JavaScript RegExp, there are a few different approaches you can use:

Use the vertical tab escape sequence `\v`: The simplest way to search for a vertical tab character is to use the vertical tab escape sequence `\v` in your regular expression.

const regex = /\v/;

Use the Unicode code point for the vertical tab character

const regex = /\u000B/;

Use a character class to match any whitespace character: If you want to match any whitespace character, including the vertical tab character, you can use a character class like `[ \t\r\n\v\f]`. 

const regex = /[ \t\r\n\v\f]/;

Example 1: Using the RegExp.test() method: The RegExp.test() method returns true if the regular expression matches the input string, and false otherwise. Here’s an example that searches for a vertical tab character in a string using RegExp.test() method.

Javascript

const str = "Hello\vworld!";
const regex = /\v/;
const hasVerticalTab = regex.test(str);
console.log(hasVerticalTab);

Output:

True

Example 2: Using the String.search() method: The String.search() method searches for a regular expression match in a string and returns the index of the first match, or -1 if no match is found. Here’s an example that searches for a vertical tab character in a string using String.search() method.

Javascript

const str = "Hello\vworld!";
const regex = /\v/;
const index = str.search(regex);
console.log(index);

Output:

5

Example 3: Using the String.match() method: The String.match() method searches for a regular expression match in a string and returns an array of the matches, or null if no match is found. Here’s an example that searches for a vertical tab character in a string using String.match() method.

Javascript

const str = "Hello\vworld!";
const regex = /\v/;
const matches = str.match(regex);
console.log(matches);

Output:

[ '\v', index: 5, input: 'Hello\vworld!' ]

Example 4: Using the RegExp.exec() method: The RegExp.exec() method searches for a regular expression match in a string and returns an array of the matches, or null if no match is found. Here’s an example that searches for a vertical tab character in a string using RegExp.exec() method.

Javascript

const str = "Hello\vworld!";
const regex = /\v/;
const match = regex.exec(str);
console.log(match);

Output:

[ '\v', index: 5, input: 'Hello\vworld!' ]

Note: The above examples assume that the input string contains a vertical tab character. If the input string does not contain a vertical tab character, the RegExp search methods will return false, -1, null, or undefined depending on the method used.