JavaScript Tutorial 03 #Array#

/* array */
var empty = [];
var primes = [2,3,5];
var misc = [1.1, true, "a"];
//
var a = new Array(10);
//
a = [1,2,3];
Object.defineProperty(a, "length", {writable: false});
a.length = 0; //a will not change

var keys = Object.keys(o); //获得o对象属性名组成的数组
var values = [];
for(var i = 0; i<keys.length; i++) {
    var key = keys[i];
    values[i] = o[key];
}
//
var a = [1,2,3];
a.join(); //"1,2,3"
a.join(" "); //"1 2 3"
a.join(""); //"123"

/* foreach */
var data = [1,2,3,4,5];
var sum = 0;
data.forEach(function(value) {
    sum += value;
});
//element, index, array
data.forEach(function(v,i,a) {
    a[i] = v + 1;
});