It is no surprise that you may need to work with different programming languages, or at least use many methods. You may not be sure how do you call a method, how many parameters does it have, or the type of objects for each parameters. During these cases, having a quick look up on the API documentation helps you immensely.
There may be many ways to go and visit an official API documentation for the language that you are working on. This does take some time, however, in comparison to two alternatives that we are going to mention now. These tools help you bring up the documentation with very few hits on your keyboard.
Dash is suitable for Mac and Zeal can be used for any other operating system of your choice.
After you have downloaded them, the first thing you need to do is grab the documentations for the language that you will be using. For example you may download Java, Ruby, JavaScript, or even frameworks like jQuery, Ruby on Rails, etc.
Then, you can set up some shortcut keys in your keyboard that can help you search anything quickly with only a few keystrokes.
Now, when you are having dilemmas about a particular method or functionality in general that you are about to use, quickly refer to the documentation that you have downloaded on your computer.
There may be some cases when something may be missing from these doc sets, but in most cases, they are very helpful.