Substring check in JavaScript
The includes() method can be used to check whether a string contains a specified substring. It returns true if substring is present. This method is case sensitive.
Syntax:
string.includes(searchvalue, start)
Parameters: This method requires 2 parameters :-
- searchvalue: Required. It specifies the substring that needs to be searched.
- start: Optional. It specifies the index from where the searching is performed. By default it is 0.
Return Value: True if the specified substring is present in string else returns false.
Example:
<!DOCTYPE html> < html > < body > < h1 >Welcome to GeeksforGeeks</ h1 > < p >Click the button to check whether < b >Geeks</ b > is present in the below string. </ p > Hello there! Welcome to GeeksforGeeks.< br >< br > < button onclick = "myFunction()" >Try it</ button > < p id = "display" ></ p > <!--script to check string contains the specified substring.--> < script > function myFunction() { var str = "Hello there! Welcome to GeeksforGeeks."; var flag = str.includes("Geeks"); document.getElementById("display").innerHTML = flag; } </ script > </ body > </ html > |
Output:
Before clicking try it button:
After clicking try it button:
Supported Browsers: The browser supported by includes() Method are listed below:
- Google Chrome 41
- Apple Safari 9
- Firefox 40
- Opera 28
- Edge 12.0