CODEWITHSUNDEEP
javascriptarrays
Silverburch
Silverburch

Reputation: 477

Finding an array of arrays... inside another array

I'm dealing with 'arrays of arrays' and trying to test if all 'sets' contained in the second array are present in the first array.

var arr = [['Netherlands','PP3a'],['Austria','PP16a'],['Estonia','PP3a'],['Luxembourg','PP3a'],['Belgium','PP3a']];

var n   = [['Luxembourg','PP3a'],['Netherlands','PP3a'],['Belgium','PP3a']];

In my example https://jsfiddle.net/mnb8jddw/ they clearly are present, but the code (which incidentally seems to work with numbers), reads false. I've obviously got myself confused and would really appreciate some help as I suspect I'm taking the wrong approach.

var arr = [
  ['Netherlands', 'PP3a'],
  ['Austria', 'PP16a'],
  ['Estonia', 'PP3a'],
  ['Luxembourg', 'PP3a'],
  ['Belgium', 'PP3a']
];
var n = [
  ['Luxembourg', 'PP3a'],
  ['Netherlands', 'PP3a'],
  ['Belgium', 'PP3a']
];

function searchForArray(haystack, needle) {
  var i, j, current;
  for (var i in haystack) {
    if (needle.length === haystack[i].length) {
      current = haystack[i];
      for (j = 0; j < needle.length && needle[j] === current[j]; ++j);
      if (j === needle.length)
        return i;
    }
  }
  return -1;
}

console.log(searchForArray(arr, n)); // -1 = false

Upvotes: 0

Views: 32

Answers (1)

cl3m
cl3m

Reputation: 2801

I'm not sure that it is the answer you are looking for, but if you are looking for a quick and dirty solution, you could try something like this:

const lookup = (ar, sets) => {
  // concatenate each entry in the searched array
  const _hashed = ar.map(i => i.join(''))
  return sets.every((set) => {
    // contatenate each entry to look for
    const _set = set.join('')
    // does the searched array contain the concatenated string?
    return _hashed.indexOf(_set) > -1
  })
}

console.log(lookup(arr, n)) // => true

Note that the order of the elements matters (ie: ['Luxembourg', 'PP3a'] will match, but ['PP3a', 'Luxembourg'] won't)

See updated fiddle

Upvotes: 1

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