javascript - javascrip数组、对象深度克隆出错？

//定义克隆函数
function cloneObject(src) {
  var o = src instanceof Array ? [] : {};
  for(var k in src) 
    o[k] = typeof src[k] === Object ? cloneObject(src[k]) : src[k];
  return o;
}

//测试代码
var srcObj = {
    a: 1,
    b: {
        b1: ["hello", "hi"],
        b2: "JavaScript"
    }
};
var abObj = srcObj;
var tarObj = cloneObject(srcObj);

srcObj.a = 2;
srcObj.b.b1[0] = "Hello";

console.log(abObj.a);
console.log(abObj.b.b1[0]);

console.log(tarObj.a);      
console.log(tarObj.b.b1[0]); 

//调试结果
 2
 Hello
 1
 Hello

第二个Hello应该是小写h的，哪里错了呢？