object_filter_map_reduce

 const user=[

    {'name':'raj',age:20},

    {'name':'raj1',age:25},

    {'name':'raj2',age:19},

    {'name':'raj3',age:30}

];

// const result=user.map(Element=>Element.name);

// for(key in result){

//     console.log(result[key]);

// }

const result1=user.reduce((sum,element)=>sum+element.age,0);

console.log(result1);

// const result=user.filter(Element=>Element.age>20);

// console.log(result);