function shadowCopy(a, b){
if(!a || typeof a !== 'object'){
return
}
if(!b || typeof b !== 'object'){
return
}
for(var key in b){
if(b.hasOwnProperty(key)){
a[key] = b[key]
}
}
}
//var o = [1, 2, 3]
// defined new empty arr
//var newB = []
//shadowCopy(newB, o)
//console.log(newB)
//console.log(newB == o)
var o = {
m: 1,
n: {
c: 2
}
}
var newB = {}
shadowCopy(newB, o)
console.log(newB)
console.log(newB == o) // false