比较2D阵列 - 寻找独特的项目

Question

I have 2 arrays and need to identity the items in array2 that do not occur in array1.

Only the 1st, 2nd and 4th elements should be compared when checking for uniqueness, the 3rd element (amount in stock) should be left out of the comparison.

var array1 = [['892','NEW','2','blue'],
     ['675','USED','2','white'],
     ['943','NEW','2','green'],
     ['121','USED','2','yellow']];

var array2 = [['892','NEW','1','blue'],
     ['892','NEW','1','yellow'],
     ['121','USED','1','blue'],
     ['121','NEW','1','blue'],
     ['121','USED','1','yellow']];

Result should be:

 result = [
     ['892','NEW','1','yellow'],
     ['121','USED','1','blue'],
     ['121','NEW','1','blue']];

I've tried reworking several solutions posted to similar questions but haven't been able to work it out for this specific situation.

Answer 1

You could take a hash table and a function which generates a key out of the given array and filter array2 by checking the hash table.

 function getKey(array) { return [0, 1, 3] .map(function (i) { return array[i]; }) .join('|'); } var array1 = [['892', 'NEW', '2', 'blue'], ['675', 'USED', '2', 'white'], ['943', 'NEW', '2', 'green'], ['121', 'USED', '2', 'yellow']], array2 = [['892', 'NEW', '1', 'blue'], ['892', 'NEW', '1', 'yellow'], ['121', 'USED', '1', 'blue'], ['121', 'NEW', '1', 'blue'], ['121', 'USED', '1', 'yellow']], hash = Object.create(null), result = []; array1.forEach(function (a) { hash[getKey(a)] = true; }); result = array2.filter(function (a) { return !hash[getKey(a)]; }); console.log(result); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 2

In js it would be something like (changed to shorter code):

array2.filter(function(val){
  return !array1.some(function(item){
    return (val[0] == item[0] && val[1] == item[1] && val[3] == item[3]);
  })
});

Answer 3

The only solution would be to compare each element of an array, with every element of the other array. When and if you find something equal, you break out of the loop with a return true. If you don't find anything just return false and add the element to your output array. I hope this helps.

Answer 4

Try this ... whatever index you want to skip just give it in index[] below code

foreach (var numberA in a) { foreach (var numberB in b) { if (numberA == numberB) { if (a.inex[3]) { }else lblDate.Text += numberA.ToString(); } } }