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Editor to share with you what the role of option explicit, I believe that most people do not know much about it, so share this article for your reference, I hope you will learn a lot after reading this article, let's go to know it!

The function of option explicit is to declare that all variables need to be defined before they can be used, otherwise the program will report an error when using undefined variables, which can avoid errors caused by errors such as name spelling.

Definition variables are not required to be displayed in VBScript, that is, variables can be used without definition, which is very convenient, but it is also prone to problems.

For example, we first define a variable named "var9" and assign it, but when we use it below, we mistakenly write the variable name as "varg". The following figure shows the code below, so that there will be no exception when the program is executed, but the processing result will not match expectations. We expect to use msgbox to output the value of var9, but output the value of varg, while var9 is not assigned and defaults to null value.

The execution result is:

The "Option Explicit" we want to say can solve the above problem. The function of "Option Explicit" is to declare that all variables need to be defined before they can be used, otherwise the program will report an error when using undefined variables, so that the result errors caused by errors such as name spelling can be avoided, and "Option Explicit" can speed up the running of the program. It saves the time of dynamically allocating variable storage space while the program is running.

Let's fine-tune the code just now and add "Option Explicit" to see the effect:

The execution result is:

The error in the program identifies the problem with our use of variables, so when programming, add "Option Explicit" to prevent unnecessary exceptions. It is worth noting that "Option Explicit" must be placed at the top of the program.

These are all the contents of the article "what are the functions of option explicit?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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