Time for yet another one of my posts on lodash, today I will be writing about the _.includes method, and why It might be useful in some situations when working on a project where lodash is part of the stack.
Still there is what the lodash includes methods does, and there are all the other ways of doing the same thing both with and without lodash, so I thought I would take a moment to write a post around this topic for what it is worth.
The includes method can be used as a way to find if a value is in an array, as it is a collection method that can be used with any object in general including arrays. In this case I just need to call the lodash includes method and pass an the array as the first argument followed by the value that I want to test if it is included or not.
One issue of concern is that it is a late method, so it will not work in older clients without a polyfill. If you do care a great deal about supporting older clients it is not just a matter of using lodash though also. However getting into that would be off topic.
When just comparing a given value to all values in an array that is one thing. However in other cases I might need to do some more complex expression for each element in an array, and when it comes to that the array some method gives me that greater flexibility when it comes to having control over what is used to find if an array includes something.
When working with an object the method will return true if one of the object values is equal to the value given, but not with the key names.
Here I have an example of the _.includes method that is used to find if a string contains a given substring.
An index value can be given as the third argument to the method. This index value will be observed as a starting index value when it comes to checking the values from left to right.
When I give a negative from index value it counts as the index value from the end of the collection.