JavaScript從JSON陣列

Question

特定記錄我有一個JSON數組是這樣的：

[{"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功能來查找和檢索吉姆記錄，由僱員（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，可以實現如下：

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

在一般情況下，如果你有對數據的任何控制，我會建議改變結構讓你的生活更輕鬆。如果您使用下面的結構，你可以直接使用records[employeeId]訪問記錄：

{ "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對象不正確;它缺少兩個逗號。它應該是：

[{"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，你可以訪問EmplyeeID 4432這樣的：

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); 
}