在 CoffeeScript 中定义匿名对象数组

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最佳答案

you can't:

this is some tricks:

items:[
(name:"value1")
(name:"value2")
]

another

items:[
true && name:"value1"
true && name:"value2"
]

this is the best:

items:[
{name:"value1"}
{name:"value2"}
]

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You can also add a coma between each object:

items:[
item1:
name1:value1
,
item2:
name:value2
]

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Simple -- place a comma by itself in a column lower than that in which you define your objects.

a = [
nameA1: valueA1
nameA2: valueA2
nameA3: valueA3
,
nameB1: valueB1
nameB2: valueB2
nameB3: valueB3
]

Will become:

var a;


a = [
{
nameA1: valueA1,
nameA2: valueA2,
nameA3: valueA3
}, {
nameB1: valueB1,
nameB2: valueB2,
nameB3: valueB3
}
];

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I think the comma solution is better, but I figured I'd add this for completeness:

a = [
{
nameA1: valueA1
nameA2: valueA2
nameA3: valueA3
}
{
nameB1: valueB1
nameB2: valueB2
nameB3: valueB3
}
]

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I ran into a related problem and found this solution. If you want an array of many single k/v objects without braces, just indent some of them. Seems to do the trick.

data = [
"2013-09-25T16:46:52.636Z":3,
"2013-09-25T16:47:52.636Z":6,
"2013-09-25T16:48:52.636Z":2,
"2013-09-25T16:49:52.636Z":7,
"2013-09-25T16:50:52.636Z":5,
"2013-09-25T16:51:52.636Z":2,
"2013-09-25T16:52:52.636Z":1,
"2013-09-25T16:53:52.636Z":3,
"2013-09-25T16:54:52.636Z":8,
"2013-09-25T16:55:52.636Z":9,
"2013-09-25T16:56:52.636Z":2,
"2013-09-25T16:57:52.636Z":5,
"2013-09-25T16:58:52.636Z":7
]

Produces:

coffee> data
[ { '2013-09-25T16:46:52.636Z': 3 },
{ '2013-09-25T16:47:52.636Z': 6 },
{ '2013-09-25T16:48:52.636Z': 2 },
{ '2013-09-25T16:49:52.636Z': 7 },
{ '2013-09-25T16:50:52.636Z': 5 },
{ '2013-09-25T16:51:52.636Z': 2 },
{ '2013-09-25T16:52:52.636Z': 1 },
{ '2013-09-25T16:53:52.636Z': 3 },
{ '2013-09-25T16:54:52.636Z': 8 },
{ '2013-09-25T16:55:52.636Z': 9 },
{ '2013-09-25T16:56:52.636Z': 2 },
{ '2013-09-25T16:57:52.636Z': 5 },
{ '2013-09-25T16:58:52.636Z': 7 } ]

It's counter-intuitive to me; you'd think that this would make sub-objects but I think the comma at the end of the line tells it to stop making properties on that object.

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Not an answer to the OP's question, but just in case you're here for the same reason I was... If you're low on Mountain Dew and use '=' instead of ':', then Coffeescript will turn your array of objects into a flat array without a compile error:

data = [
one='one'
two='two'
,
one='1'
two='2'
]

Produces

['one', 'two', '1', '2']

Insert more Mountain Dew and replace the '=' with ':'.

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You can define variable while defining array, so an ugly answer would be:

a =
items: [
item1 =
name: 'value1'
item2 =
name: 'value2'
]

It would work, but you may get warnings about "defined, but not used variables (item1, item2)". Better way would be to use underscore, variable used to omit not used variables:

a =
items: [
_ =
name: 'value1'
_ =
name: 'value2'
]

console.log JSON.stringify(a) will produce this:

  {
"items":[
{
"name":"value1"
},{
"name":"value2"
}
]
}

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I'm very happy to report after a bit of fiddling that I could get this to compile just right:

items: [
nameA: subA
nameB: subB
,
nameX: subX
nameY: subY
]

It results it just what you'd expect: a list of two anonymous objects.

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Why not:

list = []
list.push
prop1: val
prop2: val
list.push
prop1: val
prop2: val

It's still a huge improvement to me over js, very easy to read, minimal and pretty safe to write.