预定义异常

Exception是所有异常的基类，类摘要如下：

<?php 
class Exception {
	protected string $message;  // 异常消息内容
	protected int $code;  // 异常代码
	protected string $file;  // 抛出异常的文件名
	protected int $line;  // 抛出异常在该文件的行号

	public __construct([string $message = "" [, int $code = 0 [, Exception $previous = NULL]]])
	final public string getMessage(void)
	final public Exception getPrevious(void)
	final public int getCode(void)
	final public string getFile(void)
	final public int getLine(void)
	final public array getTrace(void)
	final public string getTraceAsString(void)
	public string __toString(void)
	final private void __clone(void)
}

ErrorException是错误异常，类摘要如下：

<?php 
class ErrorException extends Exception {
	protected int $severity;  // 异常级别

	public __construct([string $message = "" [, int $code = 0 [, int $severity = 1 [, string $filename = __FILE__ [, int $lineno = __LINE__ [, Exception $previous = NULL]]]]]])
	final public int getSeverity(void)
}

（全文完）