#TIL : View all parameters passed to callback function without reading docs

Time before, I often meet the situation that I forgot the parameters pass to a function (so I have to searching the API docs to read via Google). This progress can take you huge time if it repeats many times.

So I think one way to debug the parameters without reading API docs, that is pass console.log as a callback function parameter.

Examples :

[3,9,27].forEach(console.log);
// So you will get
// 3 0
// 9 1
// 27 2
// Then you know , first parameter is item, second parameter is indexed key

jQuery.ajax('/data.json').done(console.log).fail(console.error);