JavaScript从JSON阵列

Question

特定记录我有一个JSON数组是这样的：

[{"Name":"Bob", "EmployeeID":1234, "StartDate":"12/01/2011"}, 
{"Name":"Jim", "EmployeeID":4432, "StartDate":"01/12/1997"}, 
{"Name":"Heather", "EmployeeID":6643, "StartDate":"07/09/2010"}] 

如何使用Javascript功能来查找和检索吉姆记录，由雇员（4432）搜索？

Answer 1

您可以使用filter：

var records = [{"Name":"Bob", "EmployeeID":1234, "StartDate":"12/01/2011"}, 
    {"Name":"Jim", "EmployeeID":4432, "StartDate":"01/12/1997"}, 
    {"Name":"Heather", "EmployeeID":6643, "StartDate":"07/09/2010"}]; 

var result = records.filter(function(r) { return r["EmployeeID"] == 4432 })[0]||'No record found'; 

搜索功能，可以实现如下：

function findByEmployeeId(records, employeeId) { 
    return records.filter(function(r) { return r["EmployeeID"] == employeeId })[0]||null; 
} 

在一般情况下，如果你有对数据的任何控制，我会建议改变结构让你的生活更轻松。如果您使用下面的结构，你可以直接使用records[employeeId]访问记录：

{ "1234" : {"Name":"Bob", "EmployeeID":1234, "StartDate":"12/01/2011"}, 
    "4432" : {"Name":"Jim", "EmployeeID":4432, "StartDate":"01/12/1997"}, 
    "6643" : {"Name":"Heather", "EmployeeID":6643, "StartDate":"07/09/2010"} } 

Answer 2

首先，你的JSON对象不正确;它缺少两个逗号。它应该是：

[{"Name":"Bob", "EmployeeID":1234, "StartDate":"12/01/2011"}, 
{"Name":"Jim", "EmployeeID":4432, "StartDate":"01/12/1997"}, 
{"Name":"Heather", "EmployeeID":6643, "StartDate":"07/09/2010"}] 

所以，你可以访问EmplyeeID 4432这样的：

var myJSONobject = [{"Name":"Bob", "EmployeeID":1234, "StartDate":"12/01/2011"}, 
{"Name":"Jim", "EmployeeID":4432, "StartDate":"01/12/1997"}, 
{"Name":"Heather", "EmployeeID":6643, "StartDate":"07/09/2010"}]; 

function showJSON() { 
    alert(myJSONobject[1].EmployeeID); 
}