JavaScript - Metodos Array

JavaScript Array concat() Method

Uniendo dos arrays:
var hege = ["Cecilie", "Lone"];
var stale = ["Emil", "Tobias", "Linus"];
var children = hege.concat(stale);  //["Cecilie","Lone","Emil","Tobias","Linus"]

Syntax
array1.concat(array2, array3,..., arrayX)

Uniendo tres arrays:
var hege = ["Cecilie", "Lone"];
var stale = ["Emil", "Tobias", "Linus"];
var kai = ["Robin"];
var children = hege.concat(stale,kai);  //["Cecilie","Lone","Emil","Tobias","Linus","Robin"]

JavaScript Array indexOf() Method

Busca el elemento Apple en el array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var a = fruits.indexOf("Apple");  //Resultado 2

Syntax
array.indexOf(item,start)

Busca el item "Apple"en el array, empezando desde la posición 4:
var fruits = ["Banana", "Orange", "Apple", "Mango", "Banana", "Orange", "Apple"];
var a = fruits.indexOf("Apple", 4);  //Resultado 6

JavaScript Array join() Method

Une los elementos de un array dentro de un string:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var energy = fruits.join();  //"Banana,Orange,Apple,Mango"

Syntax
array.join(separator)

Usando diferentes separadores:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var energy = fruits.join(" and ");  //"Banana and Orange and Apple and Mango"

JavaScript Array pop() Method

Borra el ultimo elemento de un array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.pop();  //["Banana","Orange","Apple"]

Syntax
array.pop()

JavaScript Array push() Method

Agrega un nuevo item a un array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.push("Kiwi");  //["Banana","Orange","Apple","Mango","Kiwi"]

Syntax
array.push(item1, item2, ..., itemX)

Agrega mas de un elemento:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.push("Kiwi", "Lemon", "Pineapple");  //["Banana","Orange","Apple","Mango","Kiwi","Lemon","Pineapple"]


JavaScript Array reverse() Method

Invierte el orden del array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.reverse();  //["Mango","Apple","Orange","Banana"]

Syntax
array.reverse()

JavaScript Array shift() Method

Remove the first item of an array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.shift();  //["Orange","Apple","Mango"]

Syntax

array.shift()

JavaScript Array unshift() Method

Agrega nuevos elementos al inicio del array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.unshift("Lemon","Pineapple");  //["Lemon","Pineapple","Banana","Orange","Apple","Mango"]

Syntax
array.unshift(item1,item2, ..., itemX)

JavaScript Array slice() Method

Selecciona elementos de un array:
var fruits = ["Banana", "Orange", "Lemon","Apple", "Mango"];
var citrus = fruits.slice(1, 3);  //["Orange","Lemon"]

Syntax
array.slice(start,end)

JavaScript Array sort() Method

Ordena un array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.sort();  //["Apple","Banana","Mango","Orange"]

Syntax
array.sort(compareFunction)

Valores del parametro        
compareFunction: Es una función opcional que define un orden de clasificación alternativo. La función debe devolver un valor negativo, cero o positivo, dependiendo de los argumentos, como:
           - function(a, b){return a-b}
Cuando el método sort () compara dos valores, envía los valores a la función de comparación, y ordena los valores de acuerdo al valor (cero, negativo, positivo) devuelto.

Ordenamos los números de un array de forma ascendente:
var points = [40, 100, 1, 5, 25, 10];
points.sort(function(a, b){return a-b});  //["1","5","10","25","40","100"]

JavaScript Array splice() Method

Agrega elementos en el array:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.splice(2, 0, "Lemon", "Kiwi");  //["Banana","Orange","Lemon","Kiwi","Apple","Mango"]

Syntax
array.splice(index,howmany,item1,.....,itemX)

En la posicion 2 agregamos un nuevo elemento y removemos 1 elemento:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.splice(2, 1, "Lemon", "Kiwi");  //["Banana","Orange","Lemon","Kiwi","Mango"]

En la posicion 2, removemos 2 elementos:
ar fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.splice(2, 2);  //["Banana","Orange"]

JavaScript Array toString() Method

Convierte un array en una string:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var  x = fruits.toString();  //"Banana,Orange,Apple,Mango"

Syntax

array.toString()