perl loop

Perl next operator - for loop and if statement examples

Perl next loop FAQ: Can you demonstrate how to use the Perl next operator in a Perl loop?

Problem: You're writing code for a Perl loop, and you need to write some logic to skip over the current element in the loop, and move on to the next loop element.

The Perl loop next operator

When you're in a Perl for loop (iterating over an array or hash), and you want to move on to the next element in your array or hash, just use the Perl next operator, like this:

By Alvin Alexander on February 18, 2013

Perl loop - how to break out of a loop in Perl

Perl loop break FAQ: How do I break out of a Perl loop?

Problem: You're writing some Perl loop code (for, foreach, or while), and you have a condition where you need to break out of your loop early, and you quickly find out that Perl doesn't have a 'break' operator.

The Perl "break" statement

In many programming languages you use the break operator to break out of a loop like this, but in Perl you use the last operator to break out of a loop, like this:

By Alvin Alexander on March 21, 2013

Perl loop examples - The Perl foreach, for, while, and until loops

Perl loop FAQ: Can you share some "Perl loop" examples (Perl for loops, foreach loops, and Perl arrays)?

I've written a variety of "Perl loop" stories before, but I've never shown all the different Perl loop operators in one place before. In this Perl tutorial I'll try to provide a summary of the different Perl loop constructs.

A simple Perl array

Before showing any Perl loop examples, we'll need an array to work with. Here's a simple Perl array that contains five strings:

By Alvin Alexander on May 18, 2011

The Perl until loop examples and syntax

Perl until loop FAQ: Can you share some examples of the Perl until loop syntax?

The Perl until loop is similar to the Perl while loop, but essentially does the opposite thing. Where the Perl while operator will run this loop forever:

while ('true')
{
  # do stuff here
}

the Perl until loop will never run this loop:

By Alvin Alexander on February 18, 2013

Perl hash foreach and while - How to loop over a hash in Perl

Perl hash question: How do I traverse the elements of a hash in Perl?

Answer: There are at least two ways to loop over all the elements in a Perl hash. You can use either (a) a Perl foreach loop, or (b) a Perl while loop with the each function. I find the Perl foreach syntax easier to remember, but the solution with the while loop and the each function is preferred for larger hashes.

By Alvin Alexander on May 18, 2011
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