js count array items code example

Example 1: javascript size array

let array = [1, 2, 3];
console.log(array.length);

Example 2: typescript count array condition

let data = [ { "id": 1, "is_read": true, }, { "id": 2, "is_read": true, }, { "id": 3, "is_read": false, }, { "id": 4, "is_read": true, }, ],
length = data.filter(function(item){
  return item.is_read;
}).length;
console.log(length)