问题描述
product=[{id:1111,amount:0.01},{id:2222,amount:0.01}，{id:3333,amount:2.1}] 如何取得所有的id 并以“”分隔形式拼成字符串，同时对所有的amount求和计算 问题补充：id 并以“,”分隔形式拼成字符串 如 string ids =“1111,2222,3333”
解决方案
import java.util.List;import net.sf.json.JSONArray;import net.sf.json.JSONObject;import net.sf.json.util.JSONUtils;public class Account {private String id;private Double amount;public String getId() {return id;}public void setId(String id) {this.id = id;}public Double getAmount() {return amount;}public void setAmount(Double amount) {this.amount = amount;}public static void main(String[] args) {String json = "[{id:1111,amount:0.01},{id:2222,amount:0.01},{id:3333,amount:2.1}]";JSONArray jsonArray = JSONArray.fromObject(json);List<Account> list = (List<Account>)JSONArray.toCollection(jsonArray,Account.class);String ids = "";Double amount =0.0;for(Account a:list){System.out.println(a.getId());System.out.println(a.getAmount());ids+=a.getId()+",";amount+=a.getAmount();}ids = ids.substring(0,ids.length()-1);System.out.println(ids);System.out.println(amount);}}json-lib-2.2.3.jar,ezmorph-1.0.2.jar下测试有效。
解决方案二：
基于jquery解析json的方式var puduct = '[{"id":1111,"ammount":0.01},{"id":2222,"ammount":2.01},{"id":3333,"ammount":2.21}]' ;var jsons = jQuery.parseJSON(puduct)//console.info(jsons);var ids = [];var amount = 0; $(jsons).filter(function(){ids.push(this.id);amount += parseFloat(this.ammount);});ids = ids.join(',');console.log("ids : ",ids);console.log("amount : ",amount);//下面的方式也可以，其实质还是和存js一样就是遍历数组var ids = [];var amount = 0; $.each(jsons,function(idx,obj){ids.push(obj.id);amount += parseFloat(obj.ammount);});ids = ids.join(',');console.log("ids : ",ids);console.log("amount : ",amount);运行结果引用ids : 1111,2222,3333 amount : 4.2299999999999995 ids : 1111,2222,3333 amount : 4.2299999999999995 注意这里的结果！楼主可以自己在去查下介个为什么是这样！
解决方案三：
单纯的javascript方式var apud = [{"id":1111,"ammount":0.01},{"id":2222,"ammount":2.01},{"id":3333,"ammount":2.21}];var ids = [];var amount = 0; for(var i=0;i< apud.length;i++){ids.push(apud[i].id);amount += +apud[i].ammount;}ids = ids.join(',');console.log("ids : ",ids);console.log("amount : ",amount);
解决方案四：
用Jackson，处理json的框架http://www.cnblogs.com/hoojo/archive/2011/04/22/2024628.html
解决方案五：
这个很简单，定义一个function，然后把这个数据传递进去，遍历数组，取每个对象的属性分别进行连接和计算