function cloneObj(source, target) {
var target = target || {}
for (let key in source) {
if (source.hasOwnProperty(key)) {
if (typeof(source[key])== 'object') {
target[key]=source[key] instanceof Array?[]:{}
cloneObj(source[key],target[key])
} else {
target[key] = source[key]
}
}
}
return target
}