数组对象 去重 (id,name)

let a=[{id:1,value:'this'},{id:1,value:'is'},{id:1,value:'is'}]
let set=[...new Set(a.map(item=>item.id))]
a=a.filter((item,index)=>item.id===set[index])


let ids = fileList.map((value) => value.name);
      let idsSet = new Set(ids);
      if (idsSet.size !== ids.length) {
        this.$message.warning("附件重名,请修改文件名后重新上传");
        let obj = {};
        //利用obj 属性不能重复
        fileList = fileList.reduce((cur, next) => {
          obj[next.name] ? "" : (obj[next.name] = true && cur.push(next));
          return cur;
        }, []);
      }

 

　　

let a=[{id:1,value:'this1'},{id:2,value:'is1'},{id:1,value:'is222'},{id:2,value:'is222'}]
//let set=[...new Set(a.map(item=>item.id))]
//console.log(a.filter((item,index)=>item.id===set[index]));


//后重复的会覆盖之前的
function uniq(arr,key){
    return Object.values(arr.reduce((ret,e)=>{
        ret[e[key]]=e
        return ret
    },{}))
}


function uniqForObject(arr){
    let map=new Map()
    for(let item of arr){
        if(!map.has(item.id)){
            map.set(item.id,item)
        }
    }
    return [...map.values()]

}