In JavaScript, you can search for a specific substring within a string using the search() method. The search() method returns the index of the first occurrence of the specified substring, or -1 if the substring is not found.
Example
string.search(searchvalue)The searchvalue parameter is the substring you want to search for within the string.
example
var str = "Hello world!";
var n = str.search("world");In this example, the search() method is used to search for the substring "world" within the string "Hello world!". The variable n will contain the value 6, which is the index of the first occurrence of the substring.
If the specified substring is not found within the string, the search() method will return -1.
var str = "Hello world!";
var n = str.search("foo");In this example, the search() method is used to search for the substring "foo" within the string "Hello world!". Since the substring is not found within the string, the variable n will contain the value -1.
It’s important to note that the search() method is case-sensitive. If you want to perform a case-insensitive search, you can convert both the string and the substring to lowercase or uppercase before performing the search.
var str = "Hello world!";
var n = str.toLowerCase().search("hello");In this example, the toLowerCase() method is used to convert the string "Hello world!" to all lowercase letters before performing the search for the substring "hello". Since the search() method is case-sensitive, this will return the correct index of the first occurrence of the substring.