JSON对象超详细讲解|对象、循环对象、嵌套对象、修改和删除对象属性
1.JSON对象
JSON 对象使用在大括号{}中书写。对象可以包含多个key/value(键/值)对。
key 必须是字符串,value 可以是合法的 JSON 数据类型(字符串, 数字, 对象, 数组, 布尔值或 null)。key 和 value 中使用冒号(:)分割。每个 key/value 对使用逗号(,)分割。
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>对象详解</title></head><body><script>// 对象采用键值对var obj = {"name" : "Alan_Lowe","age" : 20,"gender" : "male"}// 访问var x = obj.name;var y = obj["age"];document.write(x + " " + y);</script></body></html>
2.循环对象
使用for-in可以访问对象的属性,类似于C++STL的auto x : s
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>对象详解</title></head><body><script>// 对象采用键值对var obj = {"name" : "Alan_Lowe","age" : 20,"gender" : "male"}// 循环对象,使用for-infor(x in obj){document.write(obj[x] + "<br>");}</script></body></html>
3.嵌套对象
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>对象详解</title></head><body><script>// 嵌套对象,即对象内放对象,和对象数组类似var obj = {"name" : "Alan_Lowe","age" : 20,"gender" : "male","hobby" : {"hobby1" : "篮球","hobby2" : "足球"}}var x = obj.hobby["hobby1"];document.write(x);</script></body></html>
4.修改值
直接等号修改:
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>对象详解</title></head><body><script>// 修改值对象属性var obj = {"name" : "Alan_Lowe","age" : 20}obj["name"] = "Alan";document.write(obj.name);</script></body></html>
5.删除对象属性
使用delete:
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>对象详解</title></head><body><script>// 删除对象属性var obj = {"name" : "Alan","age" : 20}for(x in obj){document.write(obj[x] + " ");}document.write("<br>");delete obj.name;for(x in obj){document.write(obj[x] + " ");}</script></body></html>