如何根據數據的值將數組對象轉換/過濾爲新的json對象？

Question

我有一個對象陣列是這樣的：

[{id: 1, name: 'foo', sport: 'soccer'}, 
{id: 2, name: 'bar', sport: 'basketball'}, 
{id: 3, name: 'acme', sport: 'basketball'}, 
{id: 4, name: 'xyz', sport: 'baseball'}] 

我怎樣才能變換這個陣列的對象到由運動值濾波的新javascript對象？事情是這樣的：

{ 
    soccer: [{id: 1, name: 'foo'}], 
    basketball: [{id: 2, name: 'bar'},{id: 3, name: 'acme'}], 
    baseball: [{id: 4, name: 'xyz'}] 
} 

Answer 1

你可以使用Array.prototype.reduce()https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce

事情是這樣的：

array.reduce(function (accumulator, currentValue) { 
    var sport = currentValue.sport; 
    delete currentValue.sport; 
    accumulator[sport] = accumulator[sport] || []; 
    accumulator[sport].push(currentValue) 
    return accumulator; 
}, {}); 

Answer 2

試試這個：

var test = [{id: 1, name: 'foo', sport: 'soccer'}, 
{id: 2, name: 'bar', sport: 'basketball'}, 
{id: 3, name: 'acme', sport: 'basketball'}, 
{id: 4, name: 'xyz', sport: 'baseball'}]; 

test.reduce(function(aggregator, item) { 

    if(!aggregator[item.sport]) { 
     aggregator[item.sport] = []; 
    } 

    aggregator[item.sport].push({id: item.id, name: item.name}) 

    return aggregator; 

}, {});