javascript sort array by object property

var array = [
  {name: "John", age: 34},
  {name: "Peter", age: 54},
  {name: "Jake", age: 25}
];

array.sort(function(a, b) {
  return a.age - b.age;
}); // Sort youngest firstfunction compareFirstNames( a, b ) {
  if ( a.first_name < b.first_name ){
    return -1;
  }
  if ( a.first_name > b.first_name ){
    return 1;
  }
  return 0;
}

var people =[
    {"first_name":"Carol", "age":29},
    {"first_name":"Anna", "age":32},
    {"first_name":"Bob", "age":32}
];

people.sort( compareFirstNames ); //people is now sorted by first name from a-zlist.sort((a, b) => (a.color > b.color) ? 1 : (a.color === b.color) ? ((a.size > b.size) ? 1 : -1) : -1 )