What’s the difference between “Array()” and “[]” while declaring a JavaScript array?

var a = [],            // these are the same    b = new Array(),  // a and b are arrays with length 0    c = ['foo', 'bar'],          // these are the same    d = new Array('foo', 'bar'),  // c and d are arrays with 2 strings    // these are different:    e = [3]            // e.length == 1, e[0] == 3    f = new Array(3),  // f.length == 3, f[0] == undefined;