用于if循环JavaScript的原型库

Question

I have a rather simple question that I am pretty sure I know the answer to. Are there any functions in the prototypejs library that allow you to combine a for loop with an if statement? I was thinking a cross between invoke and each so that you would iterate through an array and do single method on it, if that returns "true" then you do something, if not you don't do anything. It seems like a very common usecase so I would assume something in some js library functions like this.

var array = {Object, Object, Object}
array.each(function(item) {
  if(item.isTrue())
    doSomething();
});

Currently I do it like that.

Answer 1

From the documentation :

Enumerable#findAll

Returns all the elements for which the iterator returned a truthy value. For the opposite operation, see Enumerable#reject

EXAMPLE

var arr = ['1', '', '0', 'null', null];
arr.findAll(function(k) {
    return !!k;
}).each(function(f) {
    console.log('i was filtered by findAll and am truthy : ' + f);
});