如何求和JavaScript对象的值？

问题描述

我想对一个对象的值求和。

I'd like to sum the values of an object.

我习惯了python的位置：

I'm used to python where it would just be:

sample = { 'a': 1 , 'b': 2 , 'c':3 };
summed =  sum(sample.itervalues())

以下代码有效，但它是很多代码：

The following code works, but it's a lot of code:

function obj_values(object) {
  var results = [];
  for (var property in object)
    results.push(object[property]);
  return results;
}

function list_sum( list ){
  return list.reduce(function(previousValue, currentValue, index, array){
      return previousValue + currentValue;
  });
}

function object_values_sum( obj ){
  return list_sum(obj_values(obj));
}

var sample = { a: 1 , b: 2 , c:3 };
var summed =  list_sum(obj_values(a));
var summed =  object_values_sum(a)

我错过了什么明显的，或者这只是它的方式是什么？

Am i missing anything obvious, or is this just the way it is?

推荐答案

你可以将它全部放在一个函数中：

You could put it all in one function:

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 );

---

为了好玩，这里是另一个使用和（浏览器支持不再是一个大问题）：

---

For fun's sake here is another implementation using Object.keys() and Array.reduce() (browser support should not be a big issue anymore):

function sum(obj) {
  return Object.keys(obj).reduce((sum,key)=>sum+parseFloat(obj[key]||0),0);
}
let sample = { a: 1 , b: 2 , c:3 };

console.log(`sum:${sum(sample)}`);

但这似乎慢一点：

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