Node.js 錯誤和異常

<p>The code above generates the following result.</p>
function a() {
    throw new Error("Something bad happened!");
}
a();

function a () {
    throw new Error("Something bad happened!");
}
try {
    a();
} catch (e) {
    console.log("I caught an error: " + e.message);
}
console.log("program is still running");

try { 
   console.log("About to throw an error"); 
   throw new Error("Error thrown"); 
} catch (e) { 
   console.log("I will only execute if an error is thrown"); 
   console.log("Error caught: ", e.message); 
} finally { 
   console.log("I will execute irrespective of an error thrown"); 
} 

setTimeout(function () { 
    try { 
        console.log("About to throw an error"); 
        throw new Error("Error thrown"); 
    } catch (e) { 
        console.log("Error caught!"); 
    } 
}, 1000); 

function getConnection(callback) { 
    var connection; 
    try { 
       throw new Error("connection failed"); 
       // Notify callback that connection succeeded? 
    } catch (error) { 
       // Notify callback about error? 
    } 
} 

function getConnection(callback) { /*o2fo.com*/
    var connection; 
    try {
       // Lets assume that the connection failed 
       throw new Error("connection failed");
       // Notify callback that connection succeeded?
       callback(null, connection); 
    } catch (error) {
       // Notify callback about error? 
       callback(error, null); 
    } 
} 
// Usage 
getConnection(function (error, connection) { 
    if (error) {
       console.log("Error:", error.message); 
    } else {
       console.log("Connection succeeded:", connection); 
    } 
});