Please explain this PHP syntax
I've looked up the functions in the manual, but I still don't get this. According to the person who wrote the code, if the User enters "y" then the function (not shown here) will execute. However, because of the !
, it looks to me like the function (not shown here) will execute if the user enters something other开发者_JAVA百科 than "y".
Please explain (I"m a relative newbie so as much detail as possible would be helpful). Thanks
if(!strncasecmp(trim(fgets(STDIN)),'y',1))
fgets(STDIN)
- reads a string from standard input(keyboard in your case).
trim
- removes any spaces surrounding the user input. So if the user enters ' y'
or a 'y '
, it'll be converted to 'y'
strncasecmp
- The user might enter either uppercase Y
or lowercase y
, this function helps you to compare case insensitive way. Also this function returns 0
if the comparison is successful and then you use the !
(not operator) which changes the 0
to a 1
so that the if
test passes.
You could re-write it as:
if(strncasecmp(trim(fgets(STDIN)),'y',1) == 0)
The function strncasecmp returns 0 if there is no difference between the strings compared, hence the !
to check if they're equal.
精彩评论