格式化 JSON 对象时“{”和“[”之间的区别
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Difference between '{' and '[' when formatting JSON object
提问by Clarence
Is there any difference between '{' and '[' when formatting a JSON object?
格式化 JSON 对象时，'{' 和 '[' 之间有什么区别吗？
采纳答案by Samy Vilar
Yep one {...}is used to define a single object, while the other [...]is used to define a sequence of either objects, values or lists ...
{...}是的，一个用于定义单个对象，而另一个[...]用于定义一系列对象、值或列表......
objects are defined as such {key:object or list or value , ...}list ares nothing more than a sequence of either objects or lists or values, [objects or list or values, ... ]...
对象被定义为这样的{key:object or list or value , ...}列表只不过是对象或列表或值的序列，[objects or list or values, ... ]......
[{'value':1}, {'values':[1,2,3,3, {'a':'a', 'b':'b'}]}, 2, 3, 4]
[{'value':1}, {'values':[1,2,3,3, {'a':'a', 'b':'b'}]}, 2, 3, 4]
回答by Jitender Mahlawat
'{ }' used for Objectand '[]' is used for Arrayin json
“ { }”用于对象，“ []”用于json中的数组
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var sampleObj = {
a:1,
b:'ab'
};
var sampleArr = [1,'ab',4];
回答by Luchian Grigore
They don't have the same meaning at all. {}denote containers, []denote arrays.
它们根本没有相同的含义。{}表示容器，[]表示数组。
回答by Ravi Kumar
package ravi.kumar;
import java.util.ArrayList;
import java.lang.Object;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class SetListClass {
public static void main(String[] args) {
SetListClass SetListClass = new SetListClass();
List<String> list = new ArrayList<String>();
list.add("country");
list.add("state");
list.add("distract");
list.add("country");
System.out.println(list);
System.out.println("----------------------------------------------");
SetListClass.getset();
System.out.println("----------------------------------------------");
SetListClass.getHashMap();
}
public void getset()
{
Set<String> set = new HashSet<String>();
set.add("country");
set.add("state");
set.add("distract");
set.add("country");
System.out.println(set);
System.out.println(set.remove("country"));
System.out.println("---------------------------------------------");
System.out.println(set);
}
public void getHashMap() {
HashMap<String, Object> hashmap = new HashMap<String, Object>();
hashmap.put("country", "india");
hashmap.put("state", "bihar");
hashmap.put("district", "buxar");
System.out.println(hashmap);
}
}
output
-------
[country, state, distract, country] ------array
----------------------------------------------
[state, distract, country] ----array
true
---------------------------------------------
[state, distract]
----------------------------------------------
{state=bihar, district=buxar, country=india} ---Object
