11-06-2012
Quote:
Originally Posted by
royalibrahim
I Just want to understand whether in Perl, is it possible to iterate over a file object using a for loop as I did in my code? Perl complains no error even if you use it.
Of course, yes. You did it, right?
Why would perl complain when what you were doing was syntactically correct but logically wrong?
Never use a for (or foreach) loop to read a file. In this case, all lines from the file (depending on the input record separator) will be read in at once and stored in memory to form a list. Your loop will then iterate over the elements of this list. So, you might hit your system's memory limits.
A while loop is much much better as it reads one record at a time.
This User Gave Thanks to elixir_sinari For This Post:
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LEARN ABOUT DEBIAN
continue
continue(3tcl) Tcl Built-In Commands continue(3tcl)
__________________________________________________________________________________________________________________________________________________
NAME
continue - Skip to the next iteration of a loop
SYNOPSIS
continue
_________________________________________________________________
DESCRIPTION
This command is typically invoked inside the body of a looping command such as for or foreach or while. It returns a TCL_CONTINUE code,
which causes a continue exception to occur. The exception causes the current script to be aborted out to the innermost containing loop
command, which then continues with the next iteration of the loop. Catch exceptions are also handled in a few other situations, such as
the catch command and the outermost scripts of procedure bodies.
EXAMPLE
Print a line for each of the integers from 0 to 10 except 5:
for {set x 0} {$x<10} {incr x} {
if {$x == 5} {
continue
}
puts "x is $x"
}
SEE ALSO
break(3tcl), for(3tcl), foreach(3tcl), return(3tcl), while(3tcl)
KEYWORDS
continue, iteration, loop
Tcl continue(3tcl)