js继承的封装

<script type="text/javascript">
            function extend(source, target) {
                for(var key in source) {
                    var value = source[key];
                    target[key] = value;
                }
            }
//            extend(source, target)
            var a = {
                gender: '男',
                grade: '初三',
                group: '第五组',
                name: '李白'
            };
            var b = {};
            extend(a, b);
            b.name = "杜甫";
            console.log(b)

            var c = {};
            extend(a, c)
            c.name = "苏轼";
            console.log(c)
            //
            
            
            //es6语法   拷贝继承
            var q = {name:'李白',age:"18"}
            var w = {...q}
            console.log(w)
            var w1 = {...q,age:'20'}
            console.log(w1)
        </script>