Removing duplicate strings using javascript

Question

I have an array of 800 sentences. I want to remove all duplicates (sentences that have the same exact words, but in different order) from the array. So for example \"this is

Answer 1

How about this?

va = ["this is a sentence", "sentence this is", "sentence this is a"]
vb = {} // dictionary of combined sorted words in each sentence
vc = [] // output list of sentences without duplicates 

for (i=0;i a is sentence this)
    var combined = va[i].split(" ").sort().join(" "); 

    if (!vb[combined]){       // if set of combined sorted words doesn't exist already
        vc.push(va[i]);      // sentence isn't duplicated, push to output list
        vb[combined] = true  // add set to dictionary
    }
}

alert(vc.join("\n"))