When PS scripts executes, it is possibly create much user defined variables. So, sometimes these varibales may confuse us a lot. Here's a workaound: Most of the standard variables can be found in System.Management.Automation.SpecialVariables. If you…
javascript里怎么检查一个未定义的变量? in JavaScript null is an object. There's another value for things that don't exist, undefined. The DOM returns null for almost all cases where it fails to find some structure in the document, but in JavaScript itself undefine…