Question

取一个包含多个对象的对象。这些对象可以有一个名为number的特定键，其值为数字。如何添加具有此键number ...

的对象的所有“数字”值

var myObject = {
    item1 = {
        name: "someName",
        color: "someColor2", 
        number: intValue
     },
     item2 = {
        name: "someName2",
        color: "someColor2"
     },
     item3 = {
        name: "someName3",
        color: "someColor3", 
        number: intValue
     },
     item4 = {
        name: "someName4",
        color: "someColor4" 
     },
};

Answer 1

var sum = 0;

for (var prop in myObject)
{
   sum += myObject[prop].number || 0;
}

可能是某事的开头 ....

Answer 2

这是Array.reduce的完美用例！但是，由于您的输入是对象而不是数组，我们需要使用Object.keys来获取项目名称列表，然后该列表将驱动reducer循环。

// your object def wasn't valid, so I made my own
var myObject = {
    item1: { name: 'item one',   color: 'red',    number: 1 },
    item2: { name: 'item two',   color: 'orange', number: 2 },
    item3: { name: 'item three', color: 'yellow', number: 3 },
    item4: { name: 'item four',  color: 'green',  number: 4 },
    item5: { name: 'item five',  color: 'blue',   number: 5 },
    item6: { name: 'item six',   color: 'indigo', number: 6 },
    item7: { name: 'item seven', color: 'violet', number: 7 }
};

var total = Object.keys(myObject) //=> ['item1', 'item2', 'item3', 'item4', ...]
.reduce(function(sum, itemName) {
    return sum += myObject[itemName].number;
}, 0);

javascript：如何添加不同对象的特定键值

2 个答案: