jsonpath跟xpath
原址：http://goessner.net/articles/JsonPath/
jsonpath和xpath对比
| XPath | JSONPath | Description |
| / | $ | the root object/element |
| . | @ | the current object/element |
| / | . or [] | child operator |
| .. | n/a | parent operator |
| // | .. | recursive descent. JSONPath borrows this syntax from E4X. |
| * | * | wildcard. All objects/elements regardless their names. |
| @ | n/a | attribute access. JSON structures don't have attributes. |
| [] | [] | subscript operator. XPath uses it to iterate over element collections and for predicates . In Javascript and JSON it is the native array operator. |
| | | [,] | Union operator in XPath results in a combination of node sets. JSONPath allows alternate names or array indices as a set. |
| n/a | [start:end:step] | array slice operator borrowed from ES4. |
| [] | ?() | applies a filter (script) expression. |
| n/a | () | script expression, using the underlying script engine. |
| () | n/a | grouping in Xpath |
json例子如下：
{ "store": {
"book": [
{ "category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{ "category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
},
{ "category": "fiction",
"author": "Herman Melville",
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"price": 8.99
},
{ "category": "fiction",
"author": "J. R. R. Tolkien",
"title": "The Lord of the Rings",
"isbn": "0-395-19395-8",
"price": 22.99
}
],
"bicycle": {
"color": "red",
"price": 19.95
}
}
}
| XPath | JSONPath | Result |
/store/book/author |
$.store.book[*].author |
the authors of all books in the store |
//author |
$..author |
all authors |
/store/* |
$.store.* |
all things in store, which are some books and a red bicycle. |
/store//price |
$.store..price |
the price of everything in the store. |
//book[3] |
$..book[2] |
the third book |
//book[last()] |
$..book[(@.length-1)] $..book[-1:]
|
the last book in order. |
//book[position()<3] |
$..book[0,1] $..book[:2]
|
the first two books |
//book[isbn] |
$..book[?(@.isbn)] |
filter all books with isbn number |
//book[price<10] |
$..book[?(@.price<10)] |
filter all books cheapier than 10 |
//* |
$..* |
all Elements in XML document. All members of JSON structure. |