Is_file ($ userPath) | file_put_contents ($ xx, $ xx)

It seems that if a file is written, it will not be written. Can this be a simple explanation? I understand ifelse, but I usually use | and & amp; it is used to judge | that is, Who or who meets the needs of a person. & amp; that is, both of them must be used...

It seems that if a file is written, it will not be written. Can this be a simple explanation? There is also a working principle. if I use if else, I understand it, but it is usually used in my eyes. | and & is used for judgment. | that is, Who or who meets the requirements, & that is, both of them must comply with this subtle Writing Method -. -Can you explain it? Thank you, God!

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It seems that if a file is written, it will not be written. Can this be a simple explanation? There is also a working principle. if I use if else, I understand it, but it is usually used in my eyes. | and & is used for judgment. | that is, Who or who meets the requirements, & that is, both of them must comply with this subtle Writing Method -. -Can you explain it? Thank you, God!

Short Circuit feature. JudgmentA | BIf a is true, B is not executed. If a is false, B is executed.

Same as above. Add: the first line is judgment.UserPathWhether it is a file, if yes, then directly execute the next line of code; ifUserPathIf it is not a file, execute|AfterFile_put_contentsTo write user configuration itemsUserPath;Why do we have to do this?Because the next line needs to introduce thisUserPathFile