Edit in JSFiddle

var people = [{
  "name": "Bob",
  "dinner": "pizza"
}, {
  "name": "John",
  "dinner": "sushi"
}, {
  "name": "Larry",
  "dinner": "hummus"
}];

// Filter
var user = people.filter(function(person) {
  return person.dinner == "sushi";
});

// Map
var user =people.map(function (person) {
  if (person.dinner == "sushi") {
    return person;
  } else {
    return null;
  }
}); // => [null, { "name": "john", "dinner": "sushi" }, null]


// Reduce
var user = people.reduce(function (sushiPeople, person) {
  if (person.dinner == "sushi") {
    return sushiPeople.concat(person);
  } else {
    return sushiPeople;
  }
}, []); 

document.getElementById('output').innerHTML =(user[0].name);

<p id="output"></p>