Perl redo statement
Perl redo statement directly to the first line of the body of the loop to repeat the execution of the loop redo statement after the statement is no longer executed continue statement blocks are no longerexecuted.
continue statement can be used in the while and foreach in a loop.
Grammar
The syntax format is as follows:
redo [LABEL]
Among them LABEL is optional.
Labeled modifier LABEL of redo statement indicates that the loop control flow is transferred directly to the label modifier LABEL execution begins at the first line of the associated statement block and no longer executes redo statement and the statement after the continue sentence block;
No label modifier LABEL of redo statement means that the loop control flow is transferred directly to the first line of the current statement block to start execution instead of execution redo statement and the statement after the continue sentence block
If it is in for loop or with continue statement block, then the for incremental list in the loop and continue statement blocks are no longer executed;
Flow chart
Example
#/usr/bin/perl$a=0;while($a<10){if($a==5){$a=$a+1;redo;}print"a
=$a\\n";}continue{$a=$a+1;}
Execute the above program, and the output is as follows:
a = 0
a = 1
a = 2
a = 3
a = 4
a = 6
a = 7
a = 8
a = 9