Question

例如，如何转换：

[
  "20170101|9,4,4,2,6",
  "20170102|0,7,5,6,2"
]

进入

[
  { 
    date:"20170101"
    numbers:[9, 4, 4, 2, 6]
    sum:25
    oddOrEven:'odd',
  },
  { 
    date:"20170102",
    numbers:[0, 7, 5, 6, 2],
    sum:20,
    oddOrEven:'even',
  }
]

如果使用没有中间变量的lodash会好得多。

Answer 1

不是一行，但它会让你知道如何去做。

var a =[
  "20170101|9,4,4,2,6",
  "20170102|0,7,5,6,2"
];


a = _.map(a, function(o){
   
   var split   = o.split('|'),
       numbers = _.map(split[1].split(','), _.ary(parseInt, 1)),
       sum     = _.sum(numbers);

   return {
      date: split[0],
      numbers: numbers,
      sum: sum,
      oddOrEven: (sum % 2 == 0 ? 'even' : 'odd')
   }

});

console.log(a);

<script src="https://cdn.jsdelivr.net/lodash/4.17.4/lodash.min.js"></script>

Answer 2

你可以这样做：

library(data.table)
setDT(df)[!is.na(C),  RANK := rank(-C) , B]
df
#    A  B  C RANK
# 1: A V1  1  4.0
# 2: A V2  2  3.5
# 3: A V3  3  3.0
# 4: B V1  5  1.0
# 5: B V2  2  3.5
# 6: B V3 NA   NA
# 7: C V1  4  2.0
# 8: C V2  6  2.0
# 9: C V3  7  2.0
#10: D V1  3  3.0
#11: D V2  7  1.0
#12: D V3  8  1.0

如何通过Lodash将数组转换为对象数组

2 个答案: