Split an array of objects by property value with Javascript -

i have array objects in it. need create multiple arrays objects grouped 1 of properties value. clarify here array:

var people = [     new person("scott", "guthrie", 38),     new person("scott", "johns", 36),     new person("scott", "hanselman", 39),     new person("jesse", "liberty", 57),     new person("jon", "skeet", 38) ]; 

i want have 1 array people first name scott, 1 first name jesse , on. suggestions helpful.

to that, can loop through array entries (in any of several ways, let's use foreach here) , create object or map keyed names come across, value being arrays of entries names.

here's example using object:

// create object no prototype, doesn't have "tostring" // or "valueof", although unlikely names people have var namearrays = object.create(null);  // loop people array people.foreach(function(person) {     // name array person's name, if     var namearray = namearrays[person.firstname];     if (!namearray) {         // there wasn't one, create         namearray = namearrays[person.firstname] = [];     }     // add entry     namearray.push(person); }); 

live example:

function person(firstname, lastname, age) {    this.firstname = firstname;    this.lastname = lastname;    this.age = age;  }  var people = [    new person("scott", "guthrie", 38),    new person("scott", "johns", 36),    new person("scott", "hanselman", 39),    new person("jesse", "liberty", 57),    new person("jon", "skeet", 38)  ];    // create object no prototype, doesn't have "tostring"  // or "valueof", although unlikely names people have  var namearrays = object.create(null);    // loop people array  people.foreach(function(person) {    // name array person's name, if    var namearray = namearrays[person.firstname];    if (!namearray) {      // there wasn't one, create      namearray = namearrays[person.firstname] = [];    }    // add entry    namearray.push(person);  });    // show results  object.keys(namearrays).sort().foreach(function(firstname) {    snippet.log(      "people named " + firstname +      ": " +      namearrays[firstname].map(function(person) {        return person.firstname + " " + person.lastname;      }).join(", ")    );  });

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es2015 adds maps language, in es2015 environment might use map rather object our namearrays:

// creating map: let namearrays = new map();  // getting array: namearray = namearrays.get(person.firstname);  // adding array: namearrays.set(person.firstname, []);  // looping through map: (let [firstname, namearray] of namearrays) {     // use `firstname` , `namearray` here }