//数组去重
const a=['天',1,2,5,,'5',2,2,'5'];

const uniq=function(v){//最简方法  但是空值会变成undefined
    return [...new Set(v)]
}

const uniq2=function(v){
    let map=new Map();
    for(let i=0;i<v.length;i++){
        let number=v[i];
        if(number==undefined) continue
        if(map.has(number)){
            continue
        }else{
            map.set(number,true)
        }      
    }
    return [...map.keys()]
}