JSON計數和排序的JavaScript

Question

這是我的JSON數據：

{ 
    "EF": [ 
    { 
     "OP": "op1", 
     "pound": 2000, 
     "Date": "2012-1-13T00:00:00.000Z" 
    }, 
    { 
     "OP": "op1", 
     "pound": 1800, 
     "Date": "2014-12-6T00:00:00.000Z" 
    }, 
    { 
     "OP": "op2", 
     "pound": 300, 
     "Date": "2013-6-1T00:00:00.000Z" 
    } 
    ] 
} 

我想計數每個參數值和排序他們從最大到最小，有一個像這樣的表：

OP：OP1（2），OP2（1）磅：2000，1800，300日期： 2014-12-6T00：00：00.000Z，2013-6-1T00：00：00.000Z， 2012-1 -13T00：00：00.000Z

我試圖使用d3.nest（），但我沒有太多的成功。有什麼想法嗎？

Answer 1

//JSON from db? 
 
var json = { 
 
    "EF": [{ 
 
    "OP": "op1", 
 
    "pound": 2000, 
 
    "Date": "2012-1-13T00:00:00.000Z" 
 
    }, { 
 
    "OP": "op1", 
 
    "pound": 1800, 
 
    "Date": "2014-12-6T00:00:00.000Z" 
 
    }, { 
 
    "OP": "op2", 
 
    "pound": 300, 
 
    "Date": "2013-6-1T00:00:00.000Z" 
 
    }] 
 
}; 
 

 
//Sort based on pound 
 
json.EF.sort(function(a, b) { 
 
    if (a.pound < b.pound) return 1; 
 
    if (a.pound > b.pound) return -1; 
 
    return 0; 
 
}); 
 

 
var hash = {}; //Keep track of counts 
 
//Count the values 
 
for (var i in json.EF) { 
 
    var obj = json.EF[i]; 
 
    if (hash[obj.OP]) { 
 
    hash[obj.OP] += 1; 
 
    } else { 
 
    hash[obj.OP] = 1; 
 
    } 
 
} 
 

 
//Sorted 
 
console.log("SORTED:", json); 
 
console.log("COUNTS:", hash); 
 

 
//Now, when you loop through the json to display the values, just check the counts and display them