javascript - Counting the occurence of a string after a for loop -

i working on personal project, javascript. @ intermediary level. have created loop gives me list of random numbers. each "i", there 1 pair of integers. integers positive, different , within range (ex. between 1 , 10). let's after run loop, this:

1 vs 3 4 vs 7 5 vs 8 2 vs 3 7 vs 5 3 vs 4 1 vs 2 3 vs 5 3 vs 1 5 vs 7 ... , on... 

now, how count occurence of each pair of occurence. example, able have:

3 vs 1: occurred 2 times 7 vs 5: occurred 2 times 3 vs 5: occurred 1 time  , on... 

the order not matter, consider 3 vs 1 , 1 vs 3 same thing. realize may complicate things.

// generate pairs  var randompairs = []  (var = 0; < 10; ++i) {    var randompair = [math.floor(math.random() * 4) + 1, math.floor(math.random() * 4) + 1]    randompairs.push(randompair)  }    // count pairs  var randompairscounted = []  (var = 0; < randompairs.length; ++i) {    var = randompairs[i][0]    var b = randompairs[i][1]    if (a > b) {      var t =      = b      b = t    }    var doublicate = false    (var j = 0; j < randompairscounted.length; ++j) {      if (randompairscounted[j][0] == && randompairscounted[j][1] == b) {        randompairscounted[j][2]++        doublicate = true        break      }    }    if (doublicate == false) {      randompairscounted.push([a, b, 1])    }  }    // demo output  document.write("pairs: " + json.stringify(randompairs) + "<br><br>")  (var = 0; < randompairscounted.length; ++i) {    document.write(randompairscounted[i][0] + " vs " + randompairscounted[i][1] +                    ": occured " + randompairscounted[i][2] + " time" +                    (randompairscounted[i][2] == 1 ? "" : "s") + "<br>")  }