constarr=?[

{name:"2",age:18},

{name:"23",age:19},

{name:"2",age:19}

????];

functiongroup(arr)?{

varobj=?{};

if(Array.isArray(arr))?{

for(vari=0;i

varname=arr[i].name;

if(nameinobj)obj[name].push(arr[i]);

elseobj[name]?=?[arr[i]];

varage=arr[i].age;

if(ageinobj)obj[age].push(arr[i]);

elseobj[age]?=?[arr[i]];

????????}

??????}

returnobj;

????}

functionmax(obj)?{

varret=0;

if(obj&&typeofobj==="object")?{

for(varkeyinobj)?{

varlength=obj[key].length;

if(length>ret)ret=length;

????????}

??????}

returnret;

????}

console.log(max(group(arr))); ?// ?2