CodeJackpot - JS String Search

JS String Search

JavaScript is a powerful programming language that is widely used in web development. One of the most important features of JavaScript is its ability to manipulate strings. Strings are a sequence of characters that are used to represent text. JavaScript provides a number of methods that can be used to search for specific characters or patterns within a string. These methods are collectively known as the JS String Search methods.

Brief Explanation of JS String Search

The JS String Search methods are used to search for specific characters or patterns within a string. These methods include:

indexOf(): This method searches for a specified character or substring within a string and returns the index of the first occurrence.
lastIndexOf(): This method searches for a specified character or substring within a string and returns the index of the last occurrence.
search(): This method searches for a specified regular expression within a string and returns the index of the first occurrence.
match(): This method searches for a specified regular expression within a string and returns an array of all matches.
replace(): This method searches for a specified regular expression within a string and replaces the matches with a specified replacement string.

Code Examples

Here are some examples of how to use the JS String Search methods:

`indexOf()`

The indexOf() method searches for a specified character or substring within a string and returns the index of the first occurrence. If the character or substring is not found, it returns -1.


var str = "Hello, world!";
var index = str.indexOf("o");
console.log(index); // Output: 4

`lastIndexOf()`

The lastIndexOf() method searches for a specified character or substring within a string and returns the index of the last occurrence. If the character or substring is not found, it returns -1.


var str = "Hello, world!";
var index = str.lastIndexOf("o");
console.log(index); // Output: 8

`search()`

The search() method searches for a specified regular expression within a string and returns the index of the first occurrence. If the regular expression is not found, it returns -1.


var str = "Hello, world!";
var index = str.search(/o/);
console.log(index); // Output: 4

`match()`

The match() method searches for a specified regular expression within a string and returns an array of all matches.


var str = "The quick brown fox jumps over the lazy dog.";
var matches = str.match(/the/gi);
console.log(matches); // Output: ["the", "the"]

`replace()`

The replace() method searches for a specified regular expression within a string and replaces the matches with a specified replacement string.


var str = "The quick brown fox jumps over the lazy dog.";
var newStr = str.replace(/the/gi, "a");
console.log(newStr); // Output: "A quick brown fox jumps over a lazy dog."

JavaScript