Array.prototype.splice()

var splice_arr = ['tokyo','nagoya','osaka'];
document.write(splice_arr + '<br>');
var splice_arr2 = splice_arr.splice(1,2,'fukuoka');
document.write(splice_arr + '<br>');
document.write(splice_arr2);

See the Pen js: Array.prototype.splice() by nwstcode (@nwst) on CodePen.