Is it safe to use this kind of variable swapp开发者_开发技巧ing in php ? $a^=$b^=$a^=$b; No, because the variables may not be types that can be XORd the way you expect. The PHP idiom for swapping two
This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time,or an extraordinarily narrow situation that is not generally applic
I\'ve got to the section on operators in The Ruby Programming Language, and it\'s made me think about operator associativity. This isn\'t a Ruby question by the way - it applies to all languages.
What does -a mean in the below line. if [ \"${FILE_SYSTE开发者_JAVA技巧M}\" != \"xyz\" -a \"${FILE_SYSTEM}\" != \"abc\" ]
This is probably a dumb question came to my mind, but I think I don\'t have answer to this - How processor would find if A < B? In fact there are other things as well like A>B or A==B.
Okay, I tried looking up what >>, or shift means, but 开发者_运维知识库it\'s way over my head as this site explains it: http://www.janeg.ca/scjp/oper/shift.html
This question already has answers here: 开发者_开发百科Closed 12 years ago. Possible Duplicate: Absolute Beginner's Guide to Bit Shifting?
I tried 开发者_如何学Cecho 10**2 which prints 10**2. How to calculate the right result, 100?You can use the let builtin:
Assuming boolean a = false; I was wondering if doing: a &= b; is equivalent to a = a && b; //logical AND, a is false hence b is not evaluated.
What is the use of开发者_如何学编程 the typeof function?typeof is actually an operator, not a function, it returns you the type of the supplied operand, and returns you always[1] a string value, that
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