javascript sum object property values based on property code example

Example 1: javascript sum array values by key

var array = [
  {name: "Peter", age: 43},
  {name: "John", age: 32},
  {name: "Jake", age: 21}
];

array.reduce(function(sum, current) {
  return sum + current.age;
}, 0); // 43 + 32 + 21 = 96

Example 2: javascript object total

function sum( obj ) {
  var sum = 0;
  for( var el in obj ) {
    if( obj.hasOwnProperty( el ) ) {
      sum += parseFloat( obj[el] );
    }
  }
  return sum;
}
    
var sample = { a: 1 , b: 2 , c:3 };
var summed = sum( sample );
console.log( "sum: "+summed );