The String.prototype.includes()
method is a string method in JavaScript that returns a Boolean value indicating whether a string includes a specified search string. This method is case-sensitive, meaning that it will return true
only if the search string exactly matches a substring of the target string.
Syntax
string.includes(searchValue, start)
- searchValue: A specified search string to be searched for within a string.
-
start: The position within the string at which to begin searching for
searchString
. (Defaults to0
.)
It returns a boolean value, true
if the searched string is found within the given string; otherwise false
if not found.
Here's an example of how to use the includes()
method:
let str = 'Hello, world!';
console.log(str.includes('Hello')); // Output: true
console.log(str.includes('hello')); // Output: false
In this example, we create a string called str
and use the includes()
method to search for the substring 'Hello'
within it. Since the search string exactly matches the substring 'Hello'
, the includes()
method returns true. However, if we search for the string 'hello'
, which is not an exact match, the includes()
method returns false
.
The includes()
method also accepts an optional second argument, which is the index at which the search should start. This is useful if you want to search for a substring within a specific part of the target string.
Here's an example of using the optional second argument:
let str = 'Hello, world!';
console.log(str.includes('world', 6)); // Output: true
In this example, we search for the substring 'world'
within the string str
, starting at the index 6
. Since the string 'world'
appears at index 7
, the includes()
method returns true.
Wrapping up!
The includes()
method is a convenient and easy way to search for substrings within a string in JavaScript. It's often used in combination with other string methods, such as indexOf()
and substr()
, to perform more complex string operations.
That's all for this article, hope you learned something. Thanks for reading, catch you later.
You can also buy me a coffee that would help me grow as a frontend developer :)
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