Json字符串
Json指的是JavaScript對象表示法(javaScript Object Notation)
Json是輕量級的文本數據交換格式
Json獨立於語言
Json具有自我描述性,更容易理解
Json字典
相當於java的map
{“firstName”:“Bill”,“lastName”:“Gates”}
第二種字典格式:
{
‘‘employees’’:[
{“firstName”:“Bill”,“lastName”:“Gates”},
{“firstName”:“aaa”,“lastName”:“bbb”},
{“firstName”:“ccc”,“lastName”:“ddd”}
]
}
Json數組
[
{“firstName”:“Bill”,“lastName”:“Gates”},
{“firstName”:“aaa”,“lastName”:“bbb”},
{“firstName”:“ccc”,“lastName”:“ddd”}
]
js中json對象和字符串相互轉換
<script>
//1.json字符串轉成對象
var str1='{"firstName":"wei","lastName":"zhang"}';
var jsonObj=JSON.parse(str1);//把字符串轉成對象
//通過調用對象的屬性獲取值
console.log(jsonObj.firstName);
console.log(jsonObj.lastName);
//2.json對象轉成字符串
var str2=JSON.stringify(jsonObj);
console.log(str2);
//3.遍歷json數組
var str3='[{"firstName":"Bill","lastName":"Gates"},{"firstName":"aaa","lastName":"bbb"}{"firstName":"ccc","lastName":"ddd"}]'
//把字符串轉成對象數組
var persons=JSON.parse(str3);
for(var i=0;i<persons.length;i++){
var p=persons[i];
console.log(p.lastName+' '+p.firstName);
}
</script>