A programming pattern that USES a conditional statement to check for and handle circumstances that might cause an error.
守卫：一种编程模式。使用一些条件语句来检验和处理一些有可能导致错误的情况。
2
Have you ever used ranged based conditional formatting (such as icon sets, color scales and data bars) only to find that one of your formulas have evaluated to an error?
您是否曾经使用范围的条件格式(如图示套，颜色表和数据酒吧)才发现您的一个公式评价一个错误？
3
The simulation results show that the new algorithm has better performance, less steady residual error and lower calculation complexity than conditional ones.