我有一些格式如下的 JSON 数据：
[ {"stage1" : [{
"checkpoints" :
[
{
"id" : "checkpoint1",
"name" : "a checkpoint name 1",
"purpose" : "a string about the purpose here",
},
{
"id" : "checkpoint2",
"name" : "a checkpoint name 2",
"purpose" : "a string about the purpose here",
}
],
"stages" :
[
{
"id" : "an id here",
"name" : "a checkpoint name 1",
"purpose" : "a string about the purpose here yah",
}
]
}
]},
{"stage2" : [{
"checkpoints" :
[
{
"id" : "checkpoint1",
"name" : "a checkpoint name 1",
"purpose" : "a string about the purpose here",
},
{
"id" : "checkpoint2",
"name" : "a checkpoint name 2",
"purpose" : "a string about the purpose here",
}
],
"stages" :
[
{
"id" : "an id here",
"name" : "a checkpoint name 1",
"purpose" : "a string about the purpose here yah",
}
]
}
]},
{"stage3" : [{
"checkpoints" :
[
{
"id" : "checkpoint1",
"name" : "a checkpoint name 1",
"purpose" : "a string about the purpose here",
},
{
"id" : "checkpoint2",
"name" : "a checkpoint name 2",
"purpose" : "a string about the purpose here",
}
],
"stages" :
[
{
"id" : "an id here",
"name" : "a checkpoint name 1",
"purpose" : "a string about the purpose here yah",
}
]
}
]},
]
目前我必须参考这样的数据才能进入一个阶段：
alert(data[0].stage1[0].checkpoints.length);
为了获得第 2 阶段的数据，我必须这样做：
alert(data[1].stage2[0].checkpoints.length);
我想要做的只是使用阶段名称来访问数据，而不必在“数据”声明之后指定索引：
alert(data.stagex[0].checkpoints.length);
我不想在数据部分之后声明索引。如何重组我的 JSON，以便我可以使用阶段名称来获取我需要的数据，而无需先指定索引？