JavaScript的數組二維數組

Question

我有一個JavaScript數組這樣

var myArr = [ 

    { 
     "Year":"2015", 
     "Month":"January", 
     "Value":"15.8", 
     "District":"Anuradhapura", 
     "type":"Rainfall" 
    }, 
    { 
     "Year":"2015", 
     "Month":"January", 
     "Value":"31.1", 
     "District":"Anuradhapura", 
     "type":"Temparature" 
    }, 
    { 
     "Year":"2015", 
     "Month":"January", 
     "Value":"4", 
     "District":"Anuradhapura", 
     "type":"Wind" 
    }, 
    { 
     "Year":"2015", 
     "Month":"January", 
     "Value":"69", 
     "District":"Anuradhapura", 
     "type":"Humidity" 
    } 
] 

我需要的是把type和Value數據爲2維數組。我的最終結果應該是這樣的;

var data = [ 
     [ 
      "Rainfall", 
      158 
     ], 
     [ 
      "Temparature", 
      31.1 
     ], 
     [ 
      "Wind", 
      4 
     ], 
     [ 
      "Humidity", 
      69 
     ] 
    ] 

注意myArr結果我從後端服務，該數組的長度讓我可以動態改變。我怎樣才能做到這一點。感謝

Answer 1

試試這個：

隨着foreach功能

文檔：Array.forEach

var data = []; 

myArr.forEach(x => data.push([x.type, parseFloat(x.Value)])) 

隨着map功能

文檔：Array.Map

var data = myArr.map(x => [x.type, parseFloat(x.Value)]); 

Answer 2

可以簡單地使用Array.map功能對象陣列映射到二維陣列。

var data = myArr.map(function(o){ 
     return [o.type, o.Value] 
    }); 

此外，如果你想要的值轉換成float數字代替string，與pasreFloat

var data = myArr.map(function(o){ 
     return [o.type, pasreFloat(o.Value)] 
    }); 

Answer 3

爲此，您可以使用Arrays.map函數來得到結果：

 var data = myArr.map(function(input){ return [input.type, input.Value]; }); 

這個函數會將數組中的每個元素轉換爲另一個元素，因爲你需要一個數組數組，你的mappin g函數必須從一個對象中創建一個數組。

Answer 4

let data = []; 
myArr.map(a => { 

data.push([a.type, a.Value]); 

}); 

Answer 5

我熟悉underscore.js：你可以使用：

_.zip(_.pluck(myArr, "type"), _.pluck(myArr, "Value")); 

var myArr = [ 
 

 
    { 
 
     "Year":"2015", 
 
     "Month":"January", 
 
     "Value":"15.8", 
 
     "District":"Anuradhapura", 
 
     "type":"Rainfall" 
 
    }, 
 
    { 
 
     "Year":"2015", 
 
     "Month":"January", 
 
     "Value":"31.1", 
 
     "District":"Anuradhapura", 
 
     "type":"Temparature" 
 
    }, 
 
    { 
 
     "Year":"2015", 
 
     "Month":"January", 
 
     "Value":"4", 
 
     "District":"Anuradhapura", 
 
     "type":"Wind" 
 
    }, 
 
    { 
 
     "Year":"2015", 
 
     "Month":"January", 
 
     "Value":"69", 
 
     "District":"Anuradhapura", 
 
     "type":"Humidity" 
 
    } 
 
]; 
 

 

 
alert(JSON.stringify(_.zip(_.pluck(myArr, "type"), _.pluck(myArr, "Value"))));

<script src="http://underscorejs.org/underscore-min.js"></script>