For me, the information tends to be incomplete that it’s hard to use as a reference, which is often why I am searching in the first place. For example look at JavaScript Array reduce function in w3schools [0] and MDN [1] and try to decide the exact result when you pass only one argument to the function. MDN is very precise about the behavior and w3schools basically forces you to test and see.

[0] https://www.w3schools.com/jsref/jsref_reduce.asp [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...