Question

I need to find out, is there in array of objects object with the certain key:value
For example if I need the key ‘id’ to be unique:

arr=[
     {id:1,  attr1:'435',attr2:'sdg'},
     {id:2,  attr3:'4x35',attr2:'sdg'}
    ];

a={id:1,attr2:'nnsklnf'};
b={id:3,attr3:'kldfmlkdblng'};

function isHaveSimilar(_a,_array){
 // ... ???
}

isHaveSimilar(a,arr); // true
isHaveSimilar(b,arr); // false

Maybe there is some easier way than the rude checking of the each element? Thx)

Answer 1

function hasSimilar(needle, haystack) {
  for (item in haystack) {
    if (haystack[item].id == needle.id) {
      return true;
    }
  }
  return false;
}

hasSimilar(a, arr); // true
hasSimilar(b, arr); // false