The lodash indexof method is one of many methods in lodash that are no longer really a great selling point for the use of lodash in projects these days. There is the Array.indexOf array prototype method of course, and that is fairly well supported these days. The native string index of method works more or less the same way as lodash index of method with strings, and as such this is not one of the most compelling methods in lodash that help to win over pople who say it is a dead library.
1 - lodash indexOf and what to know before continuing
1.1 - Browser support for Array.indexOf
So one of the main reasons why you might bother with a method like _.indexOf over Array.indexOf might have to do with browser support yes? Well the thing about that is that it is not just a question of how far back support goes with a native method it is also a question of how far back does support go with the version of lodash you are using as well.
From what I have gathered the Array.indexOf method works with versions 9+ of Internet explorer, and late versions of lodash only support ie as far back as version 10 of IE. So then it is important to know what version of lodash you are using, and what needs to happen to push support backward farther if need be.
2 - A basic lodash indexof example
So if you have an array of primitives and you want to know the index of the first element from index zero forwards the the lodash indexOf method could be used to do just that.
Well that being said lets look at some other options then.
3 - Vanilla js alternatives to the lodash indexOf method
The lodash indexOf method does not bring much of anything new to the table compared to the native Array.indexOf method, and browser support with Array.indexOf is fairly good these days. This is of course not the case with all lodash methods as some of them work a little differently add additional features, and help to function as a safety net of sorts. However this is not so much the case with _.indexOf it would seem, unless you need to support ie 8 or even older browsers then that for some reason. So lets look at what we can do with just plain old vanilla js.
3.1 - The Array.indexOf method
So of course the first alternative that comes to mind is the native Array.indexOf method. This works in more or less the same fashion as the lodash .indexOf method, but it is a array prototype method. So there is no need to pass the array, just call it off the array and pass the value that you want the first index of from index zero forward.
However just like with the lodash method there is still having a greater amount of control when it comes to from where to where, and what to look for when it comes to getting one or more index values. SO lets look as some more examples.
3.2 - Using Array.forEach to get one or more index values
3.3 - Getting index values for arrays of primitives and objects with a while loop
Sometimes if you want a job done right you just have to do it yourself. Say you want a method that is like the lodash index of method or its native counterpart, but is packed with all kinds of features that allow for changing the direction in which we are looking, allow for custom functionality when it comes to what exactly we are looking for in order to log an index value, and so forth.
Well there is what can be done with a while loop, it is something where I can define a condition that is what will need to hapen in oder to stop looping rather than just looping over everything every time. I can set a starting index at the end of an array, and the loop backwards if I want also.
In addition I can make it a high order function of sorts in the sense that it can accept a function as one of its arguments and inside the body of that function I can define some custom logic that can change the behavior of the method when it comes to what it is that results in an element being pushed to an array of index values or not.
maybe something like this:
I have all kinds of defaults for it so then I can just use it like this when it comes to an array of primitives like so.
However say I have an array of objects and the text of interest is a property of each object. Also say I want to change up the logic in a way in which I do not just want to log items in that array that are just an exact pattern match for the value that I give, and I want to log index values from the end of the array backwards.
There are yet even more features that comes to mind, but you get the idea. In many cases taking the time to work something like this out is not called for, there is often a simpler solution depending on the nature of the problem of course.