Javascript String Search

Let’s start by understanding what a string is in JavaScript. In simple terms, a string is a sequence of characters enclosed within quotes. JavaScript provides many built-in methods to work with strings, and String.prototype.search() is one of them.

String.prototype.search() is a method that returns the index of the first occurrence of a specified string in another string. The syntax for using this method is:

string.search(searchValue)

Here, ‘string’ is the string in which we want to search, and ‘searchValue’ is the string we are searching for.

For example, let’s say we have a string ‘Hello, world!’. If we want to find the index of the first occurrence of the string ‘world’ in it, we can use the search method as follows:

const str = ‘Hello, world!’; const index = str.search(‘world’); console.log(index); // Output: 7

In this example, the search method returns the index ‘7’ as ‘world’ starts from the 7th position in the string ‘Hello, world!’.

We can also use regular expressions with the search method. Regular expressions are patterns used to match character combinations in strings. Let’s take a look at an example where we use a regular expression to search for a word that starts with the letter ‘j’.

const str = ‘JavaScript is an awesome language!’; const index = str.search(/\bj\w*/i); console.log(index); // Output: 0

Here, we used the regular expression /\bj\w*/i to search for a word that starts with the letter ‘j’. The ‘\b’ character is a word boundary that matches the beginning of a word. The ‘\w’ character matches any word character (letters, digits, or underscores), and the ‘*’ character matches zero or more occurrences of the preceding character. The ‘i’ character after the regular expression makes the search case-insensitive.