The return value, in turn, works similarly to an Array, returning true when the string can be found and false if not. Position is optional, which can specify where to start searching for a string, with a default value of 0.

A searchString is a parameter that indicates a string to be searched within another str. Take a look at how this method is expressed in code syntax: includes(searchString, position) In terms of working with a String, essentially, this method always performs a case-sensitive search to determine if one string can be found within another string, returning true and false values, respectively. In this case, the start value is not corresponding to the array's content, always returning the false output, regardless of how you manipulate the data afterward. includes( 'x', 150)) // Output: false console. Another example how this method works will show how you can get the false value when the start value is greater or equal to the array's length: let arr = Ĭonsole. The example we included is easy and readable, so you can guess what output you get with each query. Still, the most common example you have to learn is to work with numbers in arrays. Array use casesīecause this method is solely used to determine whether an array includes or excludes a specified value, its use cases are somewhat limited. Please note that the latter parameter is optional, and you can use the includes() method omitting it. The element stands for the value you're looking for, while the start indicates the starting position. While the first part is clear, the parameters should be elaborated on independently. Syntax-wise, this method is written like this when working with Arrays: array. As this method always works, the output you get will always include a true or false value as appropriate. This method can be used to determine whether an array includes a particular value among other entries. The crucial similarity between using the includes() method for each data set is that it returns true or false. Because of this peculiarity, reviewing both use cases in detail is essential to shedding more light on this method.

In JavaScript, the includes() method can work both with Arrays and Strings.

Operators: Addition assignment operator (+=).

String includes javascript