memoize

function memoize(func)
{
    let cache = {};

return function(x ,y)
{ if(Object.keys(cache).length == 0)
{
    cache.res = func(x,y );
cache.x = x;
cache.y = y;

console.log('first invoke');

return cache.res;

}

if( cache.x == x && cache.y == y )
{
console.log('load res from cache');
return cache.res;
}



cache.res = func(x,y );
cache.x = x;
cache.y = y;

console.log('load from invoke function...')
};
}

let
handler = memoize(function(x,y )
{
return x + y;
});

let
res = handler(5 , 10);

handler(5 , 10);
handler(5 , 10);
handler(5 , 11);
handler(5 , 11);