從現有的JSON對象中構建新的JS對象的最佳方法是什麼？

我打一個返回有各種貴重金屬，如投標價格的價格信息的JSON對象的API，問價，變化百分比，高/低，等從現有的JSON對象中構建新的JS對象的最佳方法是什麼？

我並不需要所有的屬性或對象內部的所有金屬類型，並且可能會出現我想循環對象的場景，所以我認爲只用我需要的屬性重新構建對象也許有意義。我很好奇最好的辦法是做什麼。

這裏是正在由API返回給我對象：

{ 
"gold_bid_usd_toz": "1286.32", 
"gold_ask_usd_toz": "1287.32", 
"gold_change_dollar_usd_toz": "5.72", 
"gold_change_percent_usd_toz": "0.44%", 
"gold_high_usd_toz": "1290.07", 
"gold_low_usd_toz": "1277.01", 
"gold_londonfix_am": "1278.44", 
"gold_londonfix_pm": "1274.48", 
"silver_bid_usd_toz": "17.2", 
"silver_ask_usd_toz": "17.3", 
"silver_change_dollar_usd_toz": "0.2", 
"silver_change_percent_usd_toz": "1.17%", 
"silver_high_usd_toz": "17.25", 
"silver_low_usd_toz": "16.92", 
"silver_londonfix": "16.69", 
"platinum_bid_usd_toz": "924.75", 
"platinum_ask_usd_toz": "929.75", 
"platinum_change_dollar_usd_toz": "0.78", 
"platinum_change_percent_usd_toz": "0.08%", 
"platinum_high_usd_toz": "930.74", 
"platinum_low_usd_toz": "920.5", 
"platinum_londonfix_am": "914.03", 
"platinum_londonfix_pm": "912.09", 
"palladium_bid_usd_toz": "958.94", 
"palladium_ask_usd_toz": "963.94", 
"palladium_change_dollar_usd_toz": "-2.49", 
"palladium_change_percent_usd_toz": "-0.26%", 
"palladium_high_usd_toz": "967.31", 
"palladium_low_usd_toz": "951.88", 
"palladium_londonfix_am": "919.07", 
"palladium_londonfix_pm": "919.01", 
"englehard_fabricated_gold": "1199.21", 
"englehard_fabricated_silver": "17.7000", 
"usdcad": "1.248698", 
"usdcny": "6.612501", 
"xpt_xpd_timestamp": "1507075200000" 
}

比方說，我只希望ask_usd_toz，change_dollar_usd_toz和change_percent_usd_toz金，銀，鉑和鈀。

以下是一個很好的方法，只需要我需要的數據來構建一個新對象？

destructureObject(metal) { 
    const goldPrice = metal.gold_ask_usd_toz; 
    const goldChangeLastClose = metal.gold_change_dollar_usd_toz; 
    const goldPercentChange = metal.gold_change_percent_usd_toz; 

    const silverPrice = metal.silver_ask_usd_toz; 
    const silverChangeLastClose = metal.silver_change_dollar_usd_toz; 
    const silverPercentChange = metal.silver_change_percent_usd_toz; 

    const platinumPrice = metal.platinum_ask_usd_toz; 
    const platinumChangeLastClose = metal.platinum_change_dollar_usd_toz; 
    const platinumPercentChange = metal.platinum_change_percent_usd_toz; 

    const palladiumPrice = metal.palladium_ask_usd_toz; 
    const palladiumChangeLastClose = metal.palladium_change_dollar_usd_toz; 
    const palladiumPercentChange = metal.palladium_change_percent_usd_toz; 

    const metal = { 
     gold: { 
     goldPrice: goldPrice, 
     goldChangeLastClose: goldChangeLastClose, 
     goldPercentChange: goldPercentChange 
     }, 
     silver: { 
     silverPrice: silverPrice, 
     silverChangeLastClose: silverChangeLastClose, 
     silverPercentChange: silverPercentChange 
     }, 
     platinum: { 
     platinumPrice: platinumPrice, 
     platinumChangeLastClose: platinumChangeLastClose, 
     platinumPercentChange: platinumPercentChange 
     }, 
     palladium: { 
     palladiumPrice: palladiumPrice, 
     palladiumChangeLastClose: palladiumChangeLastClose, 
     palladiumPercentChange: palladiumPercentChange 
     } 
    } 
    }

我覺得有一個更簡潔的方法來做到這一點。但也許不是。謝謝！

來源

2017-10-19 reknirt

'JSON.parse（金屬）;' – zer00ne

@ zer00ne你或許應該刪除評論。 – Archer

編輯：

function getMyObj(obj) { 

    var types = ['gold', 'silver', 'platinum', 'palladium']; 
    var namesMap = { 
     ask_usd_toz: 'price', 
     change_dollar_usd_toz: 'changeLastClose', 
     change_percent_usd_toz: 'percentChange' 
    }; 

    var myObj = {}; 

    types.forEach(function(type) { 
     for (var prop in namesMap) { 
      var key = type + '_' + prop; 
      if (obj.hasOwnProperty(key)) { 
       myObj[type] = myObj[type] || {}; 
       myObj[type][namesMap[prop]] = obj[key]; 
      } 
     } 
    }); 

    return myObj; 
} 

getMyObj(response);

哪裏response是您的JSON對象。

來源

2017-10-19 19:02:44 Andrea

完美。這正是我想我可以做的，但不能自己想出來的。謝謝。 – reknirt

@reknirt爲符合您示例的轉換進行了編輯 – Andrea

您可以使用名稱的對象來映射屬性的第一部分的組。

var data = { gold_bid_usd_toz: "1286.32", gold_ask_usd_toz: "1287.32", gold_change_dollar_usd_toz: "5.72", gold_change_percent_usd_toz: "0.44%", gold_high_usd_toz: "1290.07", gold_low_usd_toz: "1277.01", gold_londonfix_am: "1278.44", gold_londonfix_pm: "1274.48", silver_bid_usd_toz: "17.2", silver_ask_usd_toz: "17.3", silver_change_dollar_usd_toz: "0.2", silver_change_percent_usd_toz: "1.17%", silver_high_usd_toz: "17.25", silver_low_usd_toz: "16.92", silver_londonfix: "16.69", platinum_bid_usd_toz: "924.75", platinum_ask_usd_toz: "929.75", platinum_change_dollar_usd_toz: "0.78", platinum_change_percent_usd_toz: "0.08%", platinum_high_usd_toz: "930.74", platinum_low_usd_toz: "920.5", platinum_londonfix_am: "914.03", platinum_londonfix_pm: "912.09", palladium_bid_usd_toz: "958.94", palladium_ask_usd_toz: "963.94", palladium_change_dollar_usd_toz: "-2.49", palladium_change_percent_usd_toz: "-0.26%", palladium_high_usd_toz: "967.31", palladium_low_usd_toz: "951.88", palladium_londonfix_am: "919.07", palladium_londonfix_pm: "919.01", englehard_fabricated_gold: "1199.21", englehard_fabricated_silver: "17.7000", usdcad: "1.248698", usdcny: "6.612501", xpt_xpd_timestamp: "1507075200000" }, 
 
    wanted = { gold_ask_usd_toz: 'goldPrice', gold_change_dollar_usd_toz: 'goldChangeLastClose', gold_change_percent_usd_toz: 'goldPercentChange', silver_ask_usd_toz: 'silverPrice', silver_change_dollar_usd_toz: 'silverChangeLastClose', silver_change_percent_usd_toz: 'silverPercentChange', platinum_ask_usd_toz: 'platinumPrice', platinum_change_dollar_usd_toz: 'platinumChangeLastClose', platinum_change_percent_usd_toz: 'platinumPercentChange', palladium_ask_usd_toz: 'palladiumPrice', palladium_change_dollar_usd_toz: 'palladiumChangeLastClose', palladium_change_percent_usd_toz: 'palladiumPercentChange' }, 
 
    metal = {}; 
 

 
Object.keys(wanted).forEach(function (k) { 
 
    var key = k.match(/^[^_]+/)[0]; 
 
    metal[key] = metal[key] || {}; 
 
    metal[key][wanted[k]] =data[k]; 
 
}); 
 

 
console.log(metal);

.as-console-wrapper { max-height: 100% !important; top: 0; }

來源

2017-10-19 19:14:36

從現有的JSON對象中構建新的JS對象的最佳方法是什麼？

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