how to get last records of unique usernames from an array in java script

Question

I have an Array of Objects Like:

[ 
 { id: 8, username: \'peter\' ,weight:80,date:\'2019-10-14\'},
 { id: 1, username: \'harry\' ,weight:80,date:\'2019-01-01\'},         


        

Answer 1

Maps and Sets inherently only hold unique values. You can use this as following:

var myMap = [ 
 { id: 1, username: 'harry' ,weight:80,date:'2019-01-01'},
 { id: 2, username: 'harry' ,weight:84,date:'2019-02-21'},
 { id: 3, username: 'john' ,weight:80,date:'2019-03-11'},
 { id: 4, username: 'peter' ,weight:80,date:'2019-08-06'},
 { id: 5, username: 'peter' ,weight:80,date:'2019-06-11'},
 { id: 6, username: 'harry' ,weight:90,date:'2019-04-03'},
 { id: 7, username: 'john' ,weight:80,date:'2019-05-25'},
 { id: 8, username: 'peter' ,weight:80,date:'2019-10-14'},
]

var result = {};
for(i = 0; i < myMap.length; i++){
	result[myMap[i]['username']] = myMap[i];
}

console.log(Object.values(result));