數組對象合併以及轉換

將對象轉化爲數組

var arr = []
for (let i in obj) {
    arr.push(obj[i]); //屬性
    //arr.push(obj[i]); //值
}
console.log(arr);

    var obj=res.data.retObj;
             for (let i in obj) {
                  this.chargeSdkList.push(obj[i]); 
             }
           this.chargeSdkList.map(item => {
                  item.lastActiveDate = this.$utils.getTime(item.lastActiveDate);       
             });
             console.log(this.chargeSdkList);

兩數組通過id關聯，怎樣通過js把他們合併成一個數組？
a = [{id:1,age:10},{id:2,age:20},{id:3,age:30}]
b = [{id:3,sex:‘男’},{id:1,sex:‘男’},{id:2,sex:‘女’}]

  var c = [];
            a.forEach(function(val) {
                b.forEach(function(val2){
                    if(val.id===val2.id){
                        c.push({
                            id:val.id,
                            age:val.age,
                            sex:val2.sex
                        })
                    }
                })
            });
            console.log(c);

a.map(function(val) {
            b.map(function(val2){
                if(val.id===val2.id){
                    return Object.assign(val,val2);
                }
            })
        });
        console.log(a);