CODEWITHSUNDEEP
javascript
Bun
Bun

Reputation: 3137

Compare string to array of object

I come up with this solution to compare a string to an array of object. However, I don't think this is the best solution. Any suggestion on how to make this function perform better for large array of object?

var a = "blAh";
var b = [{
  "tag": "tag1",
  "icons": ["blah"]
}, {
  "tag": "tag2",
  "icons": ["Blah", "apple", "banana", "bLaH"]
}];

// Desired output "tag1, tag2"
function getTitle(tags, icon) {
  let arr = [];
  for (var i = 0; i < tags.length; i++) {
    tags[i].icons.forEach(elem => {
      if (icon.toLowerCase() === elem.toLowerCase()) {
        if (!arr.includes(tags[i].tag)) {
          arr.push(tags[i].tag);
        }
      }
    });
  }

  return arr.join(', ');
}
console.log(getTitle(b, a));

Upvotes: 0

Views: 54

Answers (1)

boehm_s
boehm_s

Reputation: 5534

for readability, I would use the following : 

var res = b.filter(el =>
  el.icons.length < 0 
    ? false
    : el.icons.map(icon =>  icon.toLowerCase()).indexOf(a.toLocaleLowerCase()) != -1
).map(el => el.tag).join(', ');

But for performances, this one would be better : 

var res = [];
var i, j;
for (i = 0; i < b.length; i++) {
  if (b[i].icons.length < 0) {
  } else {
     for (j = 0; j < b[i].icons.length; j++)
       b[i].icons[j] = b[i].icons[j].toLowerCase();
    if (b[i].icons.indexOf(a.toLocaleLowerCase()) !== -1)
      res.push(b[i].tag);
  }
}
res = res.join(', ');

Here is why :

  • indexOf is always faster than includes (or equal in old versions of chrome). benchmark
  • for loops are always faster than array methods like filter, map or reduce. benchmarks : map, filter

Also it's intresting to see that for loops are faster than indexOf in the latest version of chrome (60)

Hope it helps,
Best regards

Upvotes: 1

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