JSON Array Structure Variations - json

Question

Below are 3 JSON Array structure formats...
The first one, the one outlined at JSON.org, is the one I am familiar with:
Format #1
{"People": [
{
"name": "Sally",
"age": "10"
},
{
"name": "Greg",
"age": "10"
}
]}
The second one is a slight variation that names the elements of the array. I personally don't care for it; you don't name elements of an array in code (they are accessed by index), why name them in JSON?
Format #2
{"People": [
"Person1": {
"name": "Sally",
"age": "10"
},
"Person2": {
"name": "Greg",
"age": "10"
}
]}
This last one is another variation, quite similar to Format #2, but I have a hunch this one is incorrect because it appears to have extra curly braces where they do not belong.
Format #3
{"People": [
{
"Person1": {
"name": "Sally",
"age": "10"
}
},
{
"Person2": {
"name": "Greg",
"age": "10"
}
}
]}
Again, I'm confident that Format #1 is valid as it is the JSON Array format outlined at JSON.org. However, what about Format #2 and Format #3? Are either of those considered valid JSON? If yes, where did those formats come from? I do not see them outlined at JSON.org or on Wikipedia.

Answer 1

Both #1 and #3 are (nearly - there are commas missing) valid JSON, but encode different structures:
#1 gives you an Array of Objects, each with name and age String properties
#3 gives you an Array of Objects, each with a single Object property, each with name and age String properties.
The #2 is invalid: Arrays (as defined by [ ... ]) may not contain property names.

Answer 2

Solution For Format#1
By default:
array=[];
object={};
JSON Code:
var Json = {
People:[]
};
Json.People.push({
"name": "Sally",
"age": "10"
});
Json.People.push({
"name": "Greg",
"age": "10"
});
JSON Result:
{"People":
[
{
"name": "Sally",
"age": "10"
},
{
"name": "Greg",
"age": "10"
}
]
}