let obj={        name:'jack',        age:18,        sex:'girl'    }    let obj2={        name:'rose',        age:18,        sex:'boy'    }       var str={}    for(let key in obj){        for(let keys in obj2){            if(obj[key]!=obj2[key]){                str[key]=obj2[key]                               }        }    }    console.log(str) //{name: "rose", sex: "boy"}