Perl while cycle
while
statement when a given condition is true
the statement or group of statements is executed repeatedly. The condition is tested before the loop body executes.
Grammar
The syntax format is as follows:
while(condition)
{
statement(s);
}
Here, statement(s)
can be a single statement or a block of code madeup of several statements.
condition
can be any expression when the condition is true
loopis executed when the. When the condition is false
program flow exits the loop
Flow chart
In the chart while
key point of a loop is that the loop may not be executed at all. When the condition is false
skips the loop body and directly executes the following while
the next statement of the loop.
Example
#!/usr/bin/perl$a=10;# execute while circulate
while($a<20){printf"a's value is
:$a\\n";$a=$a+1;}
Variables in the program $a
execute the loop body less than 20:00, in the variable $a
greater than or equal to 20:00, exit the loop.
Execute the above program, and the output is as follows:
The value of a is: 10
The value of a is: 11
The value of a is: 12
The value of a is: 13
The value of a is: 14
The value of a is: 15
The value of a is: 16
The value of a is: 17
The value of a is: 18
The value of a is: 19