do coding(); while alive();

try ? {
????foo.bar();
} ? catch ?(e)? {
????alert(e.name? + ? " :? " ? + ?e.message);
}

• EvalError:?raised when an error occurs executing code in eval()
• RangeError:?raised when a numeric variable or parameter is outside of its valid range
• ReferenceError: raised when de-referencing an invalid reference
• SyntaxError: raised when a syntax error occurs while parsing code in eval()
• TypeError: raised when a variable or parameter is not a valid type
• URIError: raised when encodeURI() or decodeURI() are passed invalid parameters

上面的六種異常對象都繼承自Error對象。他們都支持以下兩種構造方法:

new ?Error();
new ?Error( " 異常信息 " );

手工拋出異常的方法如下：

try ? {
???? throw ? new ?Error( " Whoops! " );
} ? catch ?(e)? {
????alert(e.name? + ? " :? " ? + ?e.message);
}

如要判斷異常信息的類型，可在catch中進行判斷：

try ? {
????foo.bar();
} ? catch ?(e)? {
???? if ?(e? instanceof ?EvalError)? {
????????alert(e.name? + ? " :? " ? + ?e.message);
????} ? else ? if ?(e? instanceof ?RangeError)? {
????????alert(e.name? + ? " :? " ? + ?e.message);
????}
???? // ??etc
}

Error具有下面一些主要屬性：

• description: 錯誤描述 (僅IE可用).
• fileName: 出錯的文件名 (僅Mozilla可用).
• lineNumber: 出錯的行數 (僅Mozilla可用).
• message: 錯誤信息 (在IE下同description)
• name: 錯誤類型.
• number: 錯誤代碼 (僅IE可用).
• stack: 像Java中的Stack Trace一樣的錯誤堆棧信息 (僅Mozilla可用).

try ? {
????foo.bar();
} ? catch ?(e)? {
???? if ?(browserType? != ?BROWSER_IE)? {????????????????????????????
????????alert(
???????????? " name:? " ? + ?e.name? +
???????????? " \nmessage:? " ? + ?e.message? +
???????????? " \nlineNumber:? " ? + ?e.lineNumber? +
???????????? " \nfileName:? " ? + ?e.fileName? +
???????????? " \nstack:? " ? + ?e.stack);????????
????}
???? else ? {????????????????????
????????alert(
???????????? " name:? " ? + ?e.name? + ????
???????????? " \nerrorNumber:? " ? + ?(e.number? & ? 0xFFFF )? +
???????????? " \nmessage:? " ? + ?e.message " );????????
????}
}

try ? {
???? throw ? new ?Date();???? // ?拋出當前時間對象
} ? catch ?(e)? {
????alert(e.toLocaleString());???? // ?使用本地格式顯示當前時間
}