array.filter index code example

Example 1: javascript object filter

function objectFilter = (obj, predicate) => 
    Object.keys(obj)
          .filter( key => predicate(obj[key]) )
          .reduce( (res, key) => (res[key] = obj[key], res), {} );

// Example use:
var scores = {
    John: 2, Sarah: 3, Janet: 1
};

var filtered = objectFilter(scores, num => num > 1); 
console.log(filtered);

Example 2: filter

function isBigEnough(value) {
  return value >= 10
}

let filtered = [12, 5, 8, 130, 44].filter(isBigEnough)
// filtered is [12, 130, 44]