js對象數組中的某屬性值 拼接成字符串

var objs=[
    {id:1,name:'張三'},
    {id:2,name:'李四'},
    {id:3,name:'王五'},
    {id:4,name:'趙六'},
];

var idsStr = objs.map(function(obj,index){
    return obj.id;
}).join(",");

console.log(idsStr);