Jsonobject jsonarray JSON string HASHMAP arrylist data structures used in Java development

1.JSONObject

grow into this: {"Key1": value1, "Key2": value2, "Key3": Value3}

Most of the way: {Attribute 1: Property value 1, Property 2: Property value 2} important is the value of the property inside, which can put a lot of things

Key must be a string, value can be a valid JSON data type (string, number, object, array, Boolean, or null) (that is, object is possible)

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The value of the Loop property

for (var x in obj) {
Console.log (Obj[x]);
}

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Jsonarray:

In a JSON object, the property value is just a specific atom in a, and the JSON array is a combination of many atomic individuals

The array value in JSON must be a valid JSON data type (string, number, object, array, Boolean, or null). Mark as a

["Hello", 111 , True, null , [111, "Hello"] , {"1": 123, "2": [[i]} ]

These are individually tagged property values for JSON objects (a collection of theJSON object's property values is a JSON array)

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Arrylist's got some kind of element in it.

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HashMap are unordered, generally stored <string, object> these key value pairs

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Do some comparisons

As with JSON objects, values can be directly found by key

Jsonarray and Arrylist are positioned directly to the element value via the 0123 index Jsonobject and HashMap Navigate to the attribute value via key (come back to eat when thought)

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Jsonobject jsonarray JSON string HASHMAP arrylist data structures used in Java development