How to make a deep comparison of unordered arrays?

Question

I'd like compare two arrays which not necessary orderly. I tried to use ImmutableJS (fromJS), but it dont work with a unordered arrays. Please, look at example arrays which must be equals

First array

[ { Jnam: 'processor', Ci: 'New York', }, { Jnam: 'keyboard', Ci: 'Washington', }, { Jnam: 'display', Ci: 'Seattle', }, ]

Second

[ { Jnam: 'keyboard', Ci: 'Washington', }, { Jnam: 'processor', Ci: 'New York', }, { Ci: 'Seattle', Jnam: 'display', }, ]

Could you answer me what you do in that situations?

Possible duplicate of Javascript Arrays - Checking two arrays of objects for same contents, ignoring order — Gabriel Bleu
– Gabriel Bleu, Commented Nov 2, 2017 at 9:54
@RobAnthony Sort will be the last solution, that i'll choose. This array is set of objects and i'd like to work with these objects like mathematical objects, not js-object. Besides, how will i be sort these objects, if they haven't key, that according to which being sort? — AZawalar
– AZawalar, Commented Nov 2, 2017 at 10:06

Nina Scholz · Accepted Answer · 2017-11-03 11:15:05Z

You could create a hash table with the keys as first property and the values as second property and check the second array with it.

If hash is found decrement hash to check the exact count.

function getKeyValue(object) { var keys = Object.keys(object).sort(); return { key: keys.join('|'), value: keys.map(function (k) { return object[k]; }).join('|') }; } var first = [{ Jnam: 'processor', Ci: 'New York', }, { Jnam: 'keyboard', Ci: 'Washington' }, { Jnam: 'display', Ci: 'Seattle' }], second = [{ Jnam: 'keyboard', Ci: 'Washington', }, { Jnam: 'processor', Ci: 'New York' }, { Ci: 'Seattle', Jnam: 'display' }], hash = Object.create(null), count = 0, result; first.forEach(function (o) { var kv = getKeyValue(o); hash[kv.key] = hash[kv.key] || {}; hash[kv.key][kv.value] = (hash[kv.key][kv.value] || 0) + 1; count++; }); result = second.every(function (o) { var kv = getKeyValue(o); count--; if (hash[kv.key] && hash[kv.key][kv.value]) { hash[kv.key][kv.value]--; return true; } }) && !count; console.log(result); console.log(hash);

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

Collectives™ on Stack Overflow

How to make a deep comparison of unordered arrays?

1 Answer 1

1 Comment

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Linked

Related