Javascript で配列を結合するメモ

var a1;
var a2;
var a3;
var b1;
var b2;
var b3;
var i;

a1 = [1,2,3];
b1 = [4,5,6];
for (i = 0; i < b1.length; i++) {
    a1.push(b1[i]);
}
console.log(a1);
//-> [ 1, 2, 3, 4, 5, 6 ]

a2 = [1,2,3];
b2 = [4,5,6];
console.log(a2.concat(b2));
//-> [ 1, 2, 3, 4, 5, 6 ]

a3 = [1,2,3];
b3 = [4,5,6];
[].push.apply(a3, b3);
console.log(a3);
//-> [ 1, 2, 3, 4, 5, 6 ]

ES6

var a4;
var b4;

a4 = [1,2,3];
b4 = [4,5,6];
console.log([...a4, ...b4]);
//-> [ 1, 2, 3, 4, 5, 6 ]

参考

• ES6 Fiddle