Bear in mind that C, Java etc are compiled languages. The compiler can take as long as it likes to optimise code, and is likely to detect an empty loop and optimise it away. Perl does its compilation as part of its execution, and can therefore only spend a limited amount of time applying optimisations. In particular, it won't optimise away a for(;;) loop with an empty body. So the timings you see for perl are a fixed compilation overhead, followed by N executions of a sequence of opcodes which collectively increment $i, test it against a limiting value, and jump back.

You haven't shown anything apart from perl taking a time linearly proportional the the number of times the loop is executed. It's not clear to me why you find that surprising.

Dave.

In reply to Re^3: perl process slower and slower when loop number increase by dave_the_m
in thread perl process slower and slower when loop number increase by Anonymous Monk

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