常见数据类型的克隆（内含对象的深度克隆）

function clone(obj) {var copy;switch(typeof obj) {case 'undefined':break;case 'string':copy = obj;break;case 'blooean':copy = obj;break;case 'number':copy = obj;break;case 'object':if(obj === null) {obj = null;} else if(obj instanceof Array && obj.constructor == Array && Array.isArray(obj)) {copy = [];for(var i = 0; i < obj.length; i++) {copy.push(obj[i]);}} else {copy={};for(var j in obj) {copy[j] = arguments.callee(obj[j]);}};break;}return copy;}