For functions and constants, if the current namespace does not contain that function or constant, PHP's fallback mechanism will fall back to the standard PHP function.
对于函数和常量，如果当前的名称空间不包含这个函数或常量，PHP的后退机制会后退到标准的php函数。
If an XSL: function element has an XSL: fallback instruction, then an XSLT 1.0 processor ignores the XSL: function element entirely and does not execute its XSL: fallback.
如果xsl：function元素具有xsl：fallback指令，则XSLT 1.0处理程序将完全忽略x sl： function元素，不执行其xsl： fallback。
This paper describes the origin, definition and function of fallback mode of moving block system for urban rail transit.
介绍城市轨道交通中，移动闭塞系统的后备模式的由来、定义及其功能。
Based on IEEE standard and domestic and overseas engineering practice, the fallback system is studied in detail. The definition, function, operational principle and design specification are presented.
本文在结合IEEE标准以及国内外的工程实践的基础上，对后备系统进行了深入地研究，给出了后备系统的定义、功能、工作原理、设计要求。
Based on IEEE standard and domestic and overseas engineering practice, the fallback system is studied in detail. The definition, function, operational principle and design specification are presented.
本文在结合IEEE标准以及国内外的工程实践的基础上，对后备系统进行了深入地研究，给出了后备系统的定义、功能、工作原理、设计要求。
应用推荐