问题 Nginx 配置后 make 出现error: src/os/unix/ngx_process_cycle.c: In function 'ngx_start_worker_processes': src/os/unix/ngx_process_cycle.c:388:5: error: ignoring return value of 'ftruncate', declared with attribute warn_unused_result [-Werror=unused-resul
请分析以下PHP代码的输出结果: $a= 'dog'; switch($a) { case 'cat': echo "\$a is cat"; case 'dog': echo "\$a is dog"; case 'pig': echo "\$a is pig"; } 最终的输出结果是:$a is dog $a is pig 原因分析: switch会根据条件,跳转到第一个匹配的case处开始执行.case只是一个供switch跳转的标记,并没